It took me a long time to figure this out. What I finally did was take a short piece of scrap yarn in a different color to use to mark my turning chain.
This works even if you are working in half double, double, or whatever other stitch. Just chain right around the scrap yarn at whichever is the top of the turning chain (1st chain for single, 3rd chain for double, etc.).
Then you can see exactly where your last stitch is and it will help you keep your rows even.
This was also the way I learned to count my rows in crochet. I would leave the scrap yarn on every second row until I figured out how to count rows without it.