Introduction
Clothing alterations allow you to customize garments for a better fit, extend their lifespan, or update their style. This cheat sheet covers fundamental alteration techniques for common garments, essential tools, and best practices for achieving professional-looking results at home.
Essential Tools & Supplies
Basic Sewing Kit
- Sewing machine (recommended but not essential for all alterations)
- Hand sewing needles (assorted sizes)
- Thread (polyester all-purpose in neutral colors: black, white, navy, tan)
- Scissors (fabric shears and smaller detail scissors)
- Seam ripper (for opening seams and removing stitches)
- Pins (glass-head pins resist heat when ironing)
- Tailor’s chalk or fabric marking pen (for temporary marks)
- Measuring tape (flexible, non-stretching)
- Iron and ironing board (essential for professional results)
Additional Helpful Tools
- Rotary cutter and mat (for straight cuts)
- Thimble (protects finger when hand sewing)
- Pin cushion or magnetic pin holder
- Ruler (clear, see-through ruler is ideal)
- Hem gauge (for measuring and marking even hems)
- Safety pins (for gathering fabric or making adjustments)
- Needle threader (helps thread needles easily)
- Fabric weights (holds pattern pieces in place)
Taking Measurements
Body Measurements
- Chest/Bust: Fullest part of chest/bust
- Waist: Natural waistline (typically smallest part of torso)
- Hips: Fullest part of hips/seat
- Shoulder width: From shoulder point to shoulder point across back
- Sleeve length: From shoulder point to desired wrist position
- Inseam: From crotch to desired hem length
- Outseam: From waist to desired hem length along outside of leg
Garment Measurements
- Chest/Bust: Measure straight across from armpit to armpit, then double
- Waist: Measure at narrowest part of garment, then double
- Hips: Measure at widest part of lower garment, then double
- Length: Measure from shoulder/waistband to hem
- Sleeve: Measure from shoulder seam to end of sleeve
Common Pant/Trouser Alterations
Hemming Pants
- Determine length: Wear shoes you’ll typically pair with the pants
- Mark new hem: Fold up fabric to desired length, pin in place
- Measure: Ensure length is consistent on both legs
- Create fold line: Mark new fold line with chalk or pins
- Remove original hem: Use seam ripper to remove existing stitches
- Cut excess: Leave 1-1.5″ of fabric beyond new fold line
- Press: Fold along new hem line and press with iron
- Fold under raw edge: Turn raw edge under about 1/2″ and press again
- Sew: Stitch close to the inner folded edge
Hemming Jeans (Preserving Original Hem)
- Determine length: Mark where you want the new hem to fall
- Measure and mark: Measure distance between original hem and new length
- Fold and pin: Fold excess fabric up inside pant leg, original hem remains at bottom
- Press: Iron the fold to create a crisp edge
- Stitch: Sew just above the original hem stitching (use matching thread)
- Press again: Iron flat to set the stitches
Taking In Waist
- Try on inside-out: Mark with pins where waist needs adjustment
- Determine amount: Measure how much to take in (usually 1-2″ total)
- Mark center back: Use tailor’s chalk to mark adjustment area
- Remove belt loops: Carefully unpick any belt loops in the adjustment area
- Open waistband: Use seam ripper to open center back of waistband
- Open seam: Unpick center back seam several inches down
- Create new seam: Pin a new, deeper seam to achieve desired reduction
- Check fit: Try on to ensure proper fit before sewing
- Sew new seam: Stitch from top of waistband through pants
- Trim excess: Trim excess fabric, leaving 1/2″ seam allowance
- Press open: Press seam flat and reattach belt loops
Tapering Pant Legs
- Try on pants: Mark with pins where you want legs tapered
- Determine amount: Decide how much to take in at ankle (usually 1-2″ total circumference)
- Turn inside out: Lay flat with inseams and outseams aligned
- Mark taper line: Draw a gradual line from knee (or where tapering begins) to ankle
- Pin along line: Place pins along the line to hold fabric
- Sew new seam: Stitch along marked line
- Try on: Check fit before trimming excess
- Trim and finish: Cut excess fabric leaving 1/2″ seam allowance, finish raw edge
Common Shirt/Top Alterations
Hemming a Shirt
- Determine length: Try on shirt and mark desired length
- Measure: Ensure front and back are even (or intentionally different)
- Mark and cut: Leave 1″ below desired length for hem allowance
- Press up hem: Fold up 1/2″ and press, then fold again 1/2″ and press
- Pin hem: Place pins perpendicular to the fold
- Sew: Stitch close to inner folded edge
- Press: Iron finished hem flat
Shortening Sleeves
- Determine length: Mark desired finished length while wearing
- Measure hem allowance: Add 1″ to finished length for hem allowance
- Mark cutting line: Draw straight line around sleeve at cutting point
- Cut carefully: Cut along marked line
- Create hem: Fold edge 1/2″ and press, fold again 1/2″ and press
- Sew: Stitch close to inner folded edge
- Match: Repeat identical process for second sleeve
Taking In Sides of a Shirt
- Try on inside-out: Mark with pins where to take in sides
- Mark with chalk: Draw a line from armpit to hem where you’ll sew
- Ensure symmetry: Make sure both sides match
- Pin along lines: Pin fabric along marked lines
- Sew new seams: Stitch along pinned lines
- Try on: Check fit before trimming
- Trim excess: Leave 1/2″ seam allowance and finish raw edges
- Press: Press seams flat or open depending on fabric
Adjusting Darts
- Try on inside-out: Mark where bust/waist darts should be positioned
- Unpick original darts: Use seam ripper to remove existing darts
- Mark new darts: Draw new dart lines with chalk
- Pin darts: Pinch fabric and pin along marked lines
- Sew darts: Stitch from widest point to tip, tapering to nothing
- Press: Press darts toward center or down, depending on garment
Common Skirt/Dress Alterations
Hemming a Skirt or Dress
- Determine length: Try on with appropriate shoes and mark desired length
- Measure and mark: Mark all around at equal distance from floor
- Remove original hem: If necessary, unpick existing hem
- Measure hem allowance: Add 1-2″ to finished length
- Cut excess: Carefully cut along marked line
- Press new hem: Fold up 1/2″ and press, then fold again and press
- Pin and sew: Place pins perpendicular to edge and stitch
- Special fabrics: Use hem tape for delicate fabrics or rolled hem for sheers
Taking In a Waistband
- Determine amount: Pinch excess at side seams or center back
- Mark alterations: Mark with pins or chalk where to adjust
- Unpick waistband: Open waistband at side seams or center back
- Open seam: Unpick seam several inches below waistband
- Create new seam: Take in desired amount (evenly on both sides)
- Sew new seam: Stitch through waistband and skirt/dress
- Trim excess: Leave 1/2″ seam allowance
- Close waistband: Hand-stitch waistband closed
Adjusting Straps
- Try on garment: Mark where straps should sit
- Determine adjustment: Measure how much to shorten
- For shortening: Unpick straps at shoulder, fold excess under, reattach
- For lengthening: Add fabric extensions if needed
- Sew securely: Use strong stitching as straps bear weight
Basic Hand-Sewing Techniques
Slip Stitch (Invisible Hem)
- Thread needle and knot end
- Insert needle into fold of hem
- Pick up a few threads from main garment
- Return needle to hem about 1/4″ along
- Continue alternating between hem and garment
- Keep stitches small and tension even
Blind Hem Stitch
- Work from right to left
- Secure thread in hem fold
- Take tiny stitch in main fabric, catching just a thread or two
- Take longer stitch (1/4-1/2″) in hem fold
- Continue alternating between fabric and fold
- Stitches should be nearly invisible from right side
Backstitch (Strong Seam)
- Bring needle up through fabric
- Insert needle backward 1/8″ from where thread emerged
- Bring needle up 1/8″ ahead of starting point
- Continue this pattern of going back and then forward
- Creates solid line of stitching resembling machine stitch
Whipstitch (Edge Finishing)
- Bring needle up through edge of fabric
- Wrap thread over edge and insert needle from back to front
- Pull thread tight to create diagonal stitch over edge
- Continue at evenly spaced intervals
- Good for preventing fraying or joining two pieces
Advanced Alterations
Moving or Replacing a Zipper
- Mark zipper placement
- Carefully remove original zipper with seam ripper
- Press seam allowances open
- Position new zipper face down against right side of fabric
- Pin or baste in place
- Sew using zipper foot on machine
- For invisible zippers, use special invisible zipper foot
Replacing Buttons
- Remove original button
- Select replacement matching size/function
- Mark button placement
- Use doubled thread for strength
- Sew through holes multiple times
- Create thread shank for thick fabrics by wrapping thread between button and fabric
- Secure with several knots
Altering Armholes
- Try on garment inside out
- Mark where armhole needs adjustment
- Unpick sleeve at armhole
- Mark new armhole shape
- Trim excess fabric leaving seam allowance
- Reshape sleeve to match new armhole
- Pin and sew sleeve back in place
Common Fabric Types & Special Considerations
Cotton/Linen
- Properties: Breathable, easy to work with
- Handling: Pre-wash to prevent shrinkage
- Hemming: Standard hems work well
- Thread: All-purpose polyester or cotton thread
Denim/Heavy Cotton
- Properties: Durable, thick, can be difficult to sew through
- Handling: Use denim needle for machine sewing
- Hemming: Consider preserving original hem for jeans
- Thread: Heavy-duty or upholstery thread
Wool/Wool Blends
- Properties: Warm, can be bulky, may fray
- Handling: Steam rather than press directly
- Hemming: Catch stitch works well, or blind hem
- Thread: Polyester all-purpose or silk thread
Knits/Jersey/T-shirt Material
- Properties: Stretchy, can curl at edges
- Handling: Use ballpoint needle to prevent runs
- Hemming: Use double needle or zig-zag stitch to maintain stretch
- Thread: Polyester thread with slight stretch
Silk/Delicate Fabrics
- Properties: Slippery, shows needle holes
- Handling: Use fine pins and needles
- Hemming: Rolled hem or narrow hem with silk thread
- Thread: Silk thread or fine polyester
Synthetic Fabrics (Polyester/Nylon)
- Properties: Can melt under high heat
- Handling: Use low iron temperature
- Hemming: Standard methods work well
- Thread: Polyester all-purpose thread
Troubleshooting Common Problems
Puckered Seams
- Cause: Uneven tension or pulling fabric while sewing
- Solution: Use even pressure, let feed dogs move fabric naturally
Uneven Hems
- Cause: Inaccurate measuring or marking
- Solution: Use hem gauge, mark at consistent height from floor
Visible Stitching
- Cause: Thread color mismatch or large stitches
- Solution: Match thread to fabric exactly, use smaller stitches
Gaping Waistbands
- Cause: Curve of waistband doesn’t match body
- Solution: Take in center back, add darts, or use elastic
Twisted Pant Legs
- Cause: Inseam and outseam not aligned properly
- Solution: Ensure seams are directly opposite when laying flat
Best Practices & Tips
Before You Begin
- Always pre-wash fabrics before alterations to account for shrinkage
- Test techniques on scraps of similar fabric
- Double-check measurements before cutting
- Allow extra time for complex alterations
During Alterations
- Press as you go for professional results
- Try on frequently to check fit
- Use quality thread that matches fabric color exactly
- Be patient with delicate fabrics and complex alterations
Finishing Touches
- Clip threads closely when finished
- Press completed work for professional appearance
- Store altered garments properly to maintain shape
When to Seek Professional Help
- Complex tailoring on structured garments (suits, blazers)
- Expensive or sentimental items where mistakes would be costly
- Extensive resizing (more than 2 sizes up or down)
- Special fabrics like leather, fur, or heavily beaded items
Remember that alterations are a skill that improves with practice. Start with simple projects like hemming pants or taking in a seam, and gradually work up to more complex modifications as your confidence and abilities grow.