Another way to keep track is to put a spilt stich marker or safety pin into the stich you want to mark. It won't fall off that way. You won't be moving it from one needle to the other. If its getting too many rows down for you then just move it farther up in the same stitch column.
When I first started using markers I thought that was the way you're supposed to use them. It took a while before I noticed that people put them on the needles.
This way is helpful if you want to keep track of a "right side" with lots of knits and purls, something where both sides look similar.