Any sleeves I've done have been done the same way. Increase as far as the pattern says, or as wide as I want them and then knit straight, which is usually only an inch or two.
When I've knitted sleeves onto a sweater, I've just decreased ever 4 or 5 rows all the way down until it's as wide as I want it at the wrist. My arm length usually just has me decrease all the way down. If the sleeve is too wide at the top, I've decreased more dramatically until it gets to where I want it to be.
"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