Sometimes I find it helps to slip the first stitch of each row rather than knitting it. Slip it pattern-wise. By that, I mean slip it purl-wise or knit-wise based on what you would have knit if you knit the first stitch (does that make sense? I'm not sure it does). When I was first learning to knit, and then again when I was learning a new way to hold my yarn, I found that I had REALLY different tensions based on whether I was knitting or purling and it showed most often on the edges. This slip trick made a big difference. My gauge was still wonky, but my edges looked better.