Typically for Magic Loop you'd have one loop pulled out. For a smaller circumference like a sleeve, Julie recommends having two loops pulled out at all times. In order to do this, make sure you have plenty of extra needle cord to create the loops. Julie always uses 40" long knitting needles and knits the entire sweater with it by using the Magic Loop method.
It's not uncommon to have a tighter gauge while you're knitting sleeves - Julie certainly does! If you notice this just knit the sleeves on a needle size larger to maintain a consistent gauge throughout the sweater.
Have you ever struggled with the tension of stitches at the underarm of your sweater? In Cocoknits Method patterns Julie has you cast on stitches at the underarm and seam after. This not only creates a more secure underarm (a part of your sweater that receives a lot of friction and wear) but it makes your stitch tension even, ultimately making knitting in the round easier.
Curious where the end of your sleeve round should be? It's directly in the middle of the underarm. With the Cocoknits Method it's easy to spot because you will have just cast-on those stitches, making it easy to mark the middle.
If you're unfamiliar with the Cocoknits Method of knitting, it's a top-down, tailored style that's easily adjustable to your fit preferences thanks to the unique color tracking system. Please visit this page to learn more!