One of the benefits of hand knitting is you can make everything to fit! In addition to knitting a gauge swatch, one of the best ways to make sure a work-in-progress (WIP) garment is going to fit how you want is to try it on as you go. If you’re knitting with circular needles but they aren’t long enough to try the piece on without losing stitches, you can add a cable extender and a second cable just to try it on, then remove the extra cable if necessary to continue knitting. If you’re using the magic loop method (either traditional or with two circular needles) you may be able to leave them long. It’s very important to regularly check the fit on a large project such as a top-down sweater, but also important for hats, cowls, socks, etc.
Using the Traveller’s Cowl as a demonstration, the following video shows how to add the extra length of cable to be able to try on your project: