People were intrigued by doing sleeves two at a time on one needle (magic loop). There are MANY magic loop tutorials/videos that exist, so this is not a full tutorial, just progress pictures because I was picking up sleeves anyway.
You're going to want a longer circular needle for this - 32" ( I think, hard to measure after I've got the sleeves on it). You also need two balls of yarn (unless you work from the outside and inside of one ball of yarn like I do for socks but really I don't recommend following my example on that).
Step 1: Pick up the top of the sleeves. I started about 10 sts from the armpit. Do both sleeves. You're just sliding the stitches onto the needle (I keep my life line/waste yarn in when I do this).
Step 2: Push the work toward the other end of the needle so you leave a gap when you start to pick up the bottom part of the sleeve. You could join your yarn here if you want, but I like to make things difficult for myself and put the join at the underarm, so again, I am just slipping the stitches onto the needle until I get to the underarm. If you join the yarn earlier, go to step 3b
Step 3a: Use knit cast on for under arm stitches.
Step 3b: From this point on you need to knit the stitches onto the needle. This is much easier if you slip the stitches onto the other end of the needle. Don't worry about the stitches from the other sleeve yet because they'll all be transferred to the right needle. Knit until you have knit the remaining stitches from that sleeve
Step 4: take a breath, you've got one sleeve picked up! Now if you're not used to magic loop, you need to make sure when you move your work on the cable you don't pop out that loop (the purple cable sticking up in the above picture). If you did 3b, skip to 5b and use your second ball of yarn.
Step 5a: Slip the other sleeves stitches onto the cable until you get to the underarm, use knit cast on for your underarm stitches with your second ball of yarn.
Step 5b - pick up the other (left) needle, make another loop in the cable, and pick up the stitches that you will need to knit. All of the stitches are now on the needle. There is a loop of cable on the left, the needles meet for the left sleeve, then there is the right sleeve and another loop of cable. Each sleeve is joined to a different ball of yarn
Step 6 - knit the stitches on the left hand needle until both needle tips are on that side and there is still a loop on the right side of the work
Step 7: Flip it over, carefully pull out a loop of cable like you did in step 2, and keep knitting. Don't forget to change yarn strands when you get to the other sleeve.
I will typically put a stitch marker on the sleeve that I cast on first, just so I remember and don't make one sleeve a row longer than the other.
From this point, you'll knit the top of sleeve 1, top of sleeve 2, bottom of sleeve 2, bottom of sleeve 1, then repeat until you're done.
The benefit of this method is that if I do any patterning or changes or follow any whims (cables! Lace! Decreases! Colour changes!) I can do it on one sleeve and then immediately do it on the other. You will also continually work both sleeves - in order to skip one sleeve you'd have to start purling.
When it's time to cast off, you can put a stitch holder in the stitch from one sleeve while you work on casting off the other.
You do have to do some yarn management, but you get used to it and it's not so bad.
