Helpful article from Knitting Daily.
Did you know? Inside your closet are some great tools to help you knit to fit. They’re called “the clothes you already own.” (Yes, I know, that’s a very technical term, but we’ll muddle through together somehow.)
You already have a collection of tops, tanks, sweaters, cardigans, and jackets, all of which can tell you a LOT about what size sweater to knit for yourself. Some of these tops are ones you adore, some are OK, and some you do not (or cannot) wear for some reason. The ones you love are probably comfortable and fit you well; the ones you don’t like to wear probably do not fit or are uncomfortable. See: You are already an expert in fit!