Sew in sleeves

Hello! I have a pattern for a sweater that’s got sleeves that are worked even to the bind off - no decreases. Same with the body of the sweater. What’s the best way to sew the sleeves on w/o it looking messy? Couldn’t find a video on this technique.
Thanks!

http://knittinghelp.com/knitting/basic_techniques/misc.php

Scroll down to seaming. I love mattress, myself.