Method A (tube and crotch): sew each leg’s side seam and inseam into a tube. Turn one leg right side out and slip it inside the other, right sides together. Match the inseams at the crotch point, and sew the crotch from the back waist round to the fly end. Common in tailoring, because the crotch can be altered as one seam and the back seam left wide.

Method B (crotch first): sew the front crotch and back crotch first, then the inseam in one continuous seam from hem to hem, then the side seams. Common for jeans, pyjamas and children’s trousers, because seams can be felled or finished flat, and the side seams stay open for fitting last.

Both work. Method A is easier to alter at the back; method B is easier for felled inseams.

• After the fly (basted): the fly lies flat, centre fronts meet, the zip is hidden.
• After the crotch: seat smooth, no pulls from the crotch, side seams hang straight, the trouser does not twist. Sit, bend and climb a step (Module 3, Fitting issues: rise, seat, crotch and thighs).
• Before the waistband: the waist sits where wanted; ease is enough to sit.
• Before hemming: wear the shoes; mark the break.
• Children: keep try-ons short and fun; check sitting on the floor.

• Lined trousers: make the lining as a second trouser without pockets or waistband (darts as tucks), slip it inside after step 10, baste it to the waist, then attach the band over both. Hem the lining separately, about 1 in (2.5 cm) shorter (Module 2, Shrinkage, pre-washing and lining).
• Women’s side-zip trousers: no fly; the left side seam waits for the zip (Side zips and invisible zips), and a faced waist or contoured band follows.
• Men’s split back: sew the waistband halves to each leg before the centre back seam, then sew the centre back through the band (method A); the inlay stays wide.
• Half-elastic trousers: follow the basic order; the band has an elastic back.
• Left-handed makers: the order is the same; set up board, machine and table so you turn the same way each time.

• Batch work: do all stay-stitching, then all overlocking, then all darts; you change machine settings fewer times.
• Press station beside the machine.
• Keep a written list of the order taped near the machine; tick each step.
• Stop at a checkpoint at the end of a session, never mid-seam on a fly.

Copy this list onto a card for the machine, tick each step, and note the time taken.

The printable version will carry the D&D name, link and copyright line.

• Children’s pull-on: add growth hem and knee patches to the pattern; patches and patch pockets on the flat legs; method B (crotch first) so seams can be overlocked flat; elastic band with a back label; growth hem last.
• Kurta pyjama (straight or Aligarh style): pockets in the side seams if wanted; side seams and inseams with French or overlocked seams; crotch, double-stitched; nada casing with holes at the centre front; turned-and-stitched hems.
• Palazzo: side-seam pockets; seams; crotch; a separate elastic band or a faced waist with side zip; let it hang for a day before hemming.

1. Sew everything you can on flat pieces first.
2. Do the same step on both legs before moving on; they stay matched.
3. Label pieces on the wrong side so legs are not swapped.
4. Baste, try, then stitch at every checkpoint.
5. Finish pressed-open seams flat before sewing them.
6. Leave side seams wide until the fit is confirmed.
7. Use a test trouser (toile) in cheap cotton for any new pattern.
8. Double-stitch the crotch on every trouser.
9. Write down the time each stage takes; it is your costing data.
10. Stop and press before every crossing seam.
11. What professionals do differently: they follow the same order every time, and check before each point of no return (D&D ebook ch. 47).

Pockets forgotten before the side seams

1. Unpick the side seam around the pocket area and insert them.
2. Patch pockets can be added by opening the side seam and laying the leg flat.
3. Prevention: keep the written order beside the machine.

The legs twist after closing

1. Check side seams and inseams were sewn in the same direction; resew one.
2. Check grainlines; recut if far out.
3. Prevention: same direction for both legs; grain checked at cutting.

The crotch points do not meet

1. Unpick and re-match the inseams at the crotch.
2. Check both legs had equal inseam allowances.
3. Prevention: pin the crotch point first.

The fly does not meet the waistband

1. Adjust the band extension.
2. Re-mark centre fronts.
3. Prevention: baste and check before the band.

The waist is bigger than the band

1. Ease it in evenly.
2. Take in the side seams or centre back slightly.
3. Prevention: stay-stitch the waist early.

The fit is wrong after the waistband

1. Unpick the band at the centre back and adjust.
2. Use the split band if it is a men’s trouser.
3. Prevention: try on before the band.

The child has outgrown it before it is finished

1. Let out side seams and use the growth hem.
2. Switch to an adjustable waist.
3. Prevention: add growth room and finish children’s trousers quickly.

• Myth: the order in a pattern leaflet is the only right one. Many orders work; flat-first is the rule.
• Mistake: hemming before the waistband.
• Mistake: skipping try-ons.

1. Beginner: sew a child’s pull-on trouser in the order above.
2. Improver: sew a toile with method A and another with method B; compare.
3. Confident: make a full basic tailored trouser with three try-ons logged.

As a hobby: once the order is familiar, a pull-on trouser fits into one weekend.

For earning: a fixed order makes timing, costing and quality predictable; batch steps across several orders.

For teaching: give learners the order on a card and tick off steps together.

• Pack unfinished work flat with all pieces and notions together.
• Finish with the checks in Finishing touches and the final quality check.

• Can you list the twelve steps of a basic trouser?
• Do you know when to try on?
• Can you explain methods A and B?
• Do you sew pockets before side seams?

Quiz

1. Why is the fly sewn before the side seams? Answer: it needs flat fronts.
2. Which leg-closing method suits tailored alteration? Answer: method A (tube and crotch).
3. When is the hem marked? Answer: after the waistband, with shoes on.
4. Where does the lining go in? Answer: before the waistband, basted at the waist.

• Order of construction: the sequence of sewing steps.
• Toile: a test trouser in cheap cloth.
• Checkpoint: a planned try-on before a point of no return.
• Batching: doing the same step on many pieces at once.

• Main source: D&D’s own trousers ebook, chapters 41–47 (sequence and checkpoints), with general, widely taught practice.
• Times are rough and vary widely. Teacher to check D&D’s preferred order.