Hem trousers with a double-fold hem

Put the trousers on with the shoes you plan to wear with them, and pin the new length at the point where you want the hem to break. If you'd rather not pin them on yourself, measure the finished leg length from a pair of trousers that already fits and use that measurement instead.

Take the trousers off and mark the fold line all the way around each leg with tailor's chalk, checking with a ruler that the line stays level with the floor.

Measure 4 cm (1.5 in) below the chalk line for the hem allowance, mark it, and trim off the excess fabric with scissors along that line.

If you're reusing fabric from the original hem, unpick the old stitching with a seam ripper and press the leg flat before continuing.

Press the raw edge under by 1 cm (3/8 in) all the way around each leg. This first fold sits inside the second fold and hides the cut edge.

Fold again along the chalk line so the pressed edge tucks inside, enclosing the raw edge completely. Press this second fold flat and pin it every 5 cm (2 in) around the leg.

Thread the machine with polyester thread that matches the trousers, fit a universal 80/12 needle (a 90/14 jeans needle for heavy denim), and set stitch program 00 (straight stitch) to a length of 2.8-3 mm — go up to 3.5 mm on thick denim so the stitches don't sit too close together and pucker the fabric.

Working from the inside of the leg, backtack a few stitches with the reverse button, then edge-stitch close to the inner fold all the way around. At the thick bumps where the side seams cross, slow down and turn the handwheel toward you by hand for a few stitches, so the needle doesn't hit the extra layers and deflect or break.

Sew a little past your starting point, overlap the stitching by about 1 cm (3/8 in), and backtack again to finish off the seam.

Press the finished hem flat from the inside, then check it from the right side — the line of stitching should sit an even distance from the folded edge all the way around.