I've worked sweaters with cables thrown in the middle after a period of stockinette and generally had to add 2-3 stitches per cable.
Since a sleeve changes diameter as you work it, you could try it on and change the amount of increases/decreases you would normally make.
(Suzie's idea is, of course, the most rational, but I'm less methodical!)
"Trust the pattern!"
Time flies like an arrow, but fruit flies like a banana.
Hop aboard while we follow the cloud-covered van of knitting harmony, man!! Woooo!! --Hedgehog
IngridKH on Ravelry