I do. I set down markers (usually staves if I'm outside) at my beginning and ending points. Many forms have a certain ending point if done correctly; for example, at the end of short form 1 you will end up in exactly the same spot where you started at the end of the form if you do it correctly.
I also often have a friend videotape me doing forms and techniques; it lets me catch a lot of mistakes I would never otherwise have seen.
The idea of doing forms in sand does sound pretty good; I think I'll try that next time I'm at the beach.![]()