My mother is knitting garments! She's a multi-talented crafter who most recently has done miniature quilts and Native American-style beadwork. She's known how to knit (and crochet) for many years, and she let me teach her to knit socks after it became apparent that I couldn't produce them for her fast enough. But I haven't seen her make a sweater since I was a toddler (the red, white, and navy Fair Isle I wore to kindergarten is still around here somewhere, I think!).
Mom's sweater knitting has reminded me of just how much information about finishing isn't included in the average pattern. Many important decisions that affect the ease and appearance of seams and other details are made, not during the sewing-up process, but during the knitting of the pieces. Here are three suggestions for preparing the pieces of conventionally-constructed sweaters so that you won't dread the sewing and will be proud of the result.
Casting on: When you cast on for a piece that will later have a seam begin at its corner, leave a tail long enough to sew the seam. You'll have two fewer ends to weave in. How long a tail? For a mattress-stitched side seam, you need at least 1 1/2 times the length of the seam plus a tail to weave in. Err on the long side. To keep the long tail under control while you knit, wrap it around a bread tie (thanks to Lily Chin and the TV show Knitty Gritty for that hint!).
Edge stitches: If the side edges of the piece you're working on will end up in a seam, or have stitches picked up along them, keep the stitches nearest each edge (called selvedge stitches) as plain as possible. Ideally, keep the two stitches at each edge in stockinette or reverse stockinette. Work decreases one or two stitches in from the edge. If you work increases at the edges, place each new stitch two stitches in from the edge. This is easy for "make one" increases because they are worked between stitches; however, for Kf&b increases, remember that the bump which becomes the new stitch falls to the left of the stitch in which you increase. In order for the bump to occur two stitches from the edge, increase in the second stitch at the beginning of the row but the third stitch from the end. If you're really fussy (or just adventurous), use the mirror-image to Kf&b that I describe in this earlier post; since this increase produces a new stitch to the right of the stitch in which it's worked, work it in the second-to-last stitch.
New skeins: Begin a new skein only at the beginning of a row (unless you are splicing the ends together), so that you can weave the ends into a seam allowance later. Yes, this will waste a little yarn, but it's worth it. Be careful with the front pieces of cardigans which have knitted-in bands; join a new skein at a side edge, not a front edge.
This'll get you started. Some other time we'll have to talk about short row shoulder shaping.