If you're working garter stitch, you can pretty much pick which side is the right side. In that case, you really only need to know right from wrong when you're doing shaping. Just pick a side and tie a little piece of yarn on it, or use the tail.
"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