A garment is only as good as its finishing, so it's worth taking your time here. Start by blocking each piece, then press following the instructions on your ball band, leaving any ribbing unpressed. Give the edges particular attention, since well-pressed edges make the sewing up ahead both easier and neater. Where the ball band asks you not to press at all, lay a damp white cotton cloth over the blocked pieces instead and leave them to stand, which has the same settling effect.

Weave in every end neatly, working along the selvedge or at a colour join. As you begin stitching pieces together, match colour and texture carefully wherever two edges meet. Back stitch or mattress stitch both work well for the main seams; join ribs and neckbands with mattress stitch unless your pattern says otherwise.

With the pattern instructions complete, join the left shoulder seam and the neckband seam first, as described above. From there, attach the sleeves to the body using whichever method your pattern specifies:

Straight cast-off sleeves: line up the centre of the sleeve's cast-off edge with the shoulder seam, then sew the sleeve top to the body, following any markers given.

Square set-in sleeves: line up the centre of the cast-off edge with the shoulder seam, and set the sleeve head into the armhole so the straight sides at the top meet the cast-off stitches at a neat right angle, front and back.

Shallow set-in sleeves: line up the centre of the cast-off edge with the shoulder seam, matching the decreases at the start of the armhole shaping to those at the top of the sleeve, then ease the sleeve head into the armhole.

Set-in sleeves: line up the centre of the cast-off edge with the shoulder seam and ease the sleeve head into the armhole.

Finish by joining the side and sleeve seams, slip stitching any pocket edgings and linings into place, and sewing on buttons to line up with their buttonholes. Leave ribbed welts, neckbands and any garter stitch unpressed throughout, and wash as directed on the ball band.