I’m not comfortable knitting on circular needles because I have always knitted with straight needles using the French method (or English method, I don’t know): I hold the straight needle under my arm and the wool in my right hand. So I always knit flat. I knitted the whole sweater flat on straight needles, and finished with an invisible seams on one side and on each sleeve.
This is the first time I knit a top-down sweater. I was a bit afraid of not having a nice border because I find the ribbing more elastic and beautiful when they are at the beginning. But here, it’s not so bad. To bind off, I used needles a little bigger than for the sweater, and I knitted the stitches as they are.