First, a tip I learned from somewhere on Pinterest, when sewing zippers use scotch tape to tape down zippers instead of pinning. It worked like a charm, much faster and easier than pinning.
Second, I've been doing this for a while, and hands down, this is the best way to sew sleeves. I swear by this method instead of the cumbersome method that usually comes with pattern instructions. No more fear for fitting sleeves into the armhole, and I only use one pin for each sleeve, at the shoulder seam:
- Join the front and back at shoulders, but NOT at body side seams. Sew, then press open the shoulder seams.
- Pin the tip top of sleeve to the shoulder seam. Sew from top to underarm on the front (or the back),
- Then sew from the top to the underarm of back (or front.)
- Join sleeves in round and body in round, starting from the cuff, sew sides of sleeves together to underarm, then continue onto side seam from underarm to hem. (if you have to, trim off a little so the sleeves and body meet at the same place at underarm.)
Basically keep the clothing flat, and work in flat as much as possible before sewing on the main side seam.