If you ask me, the best check is looking at your hands. I've never had a dream where my hands looked as they should (big dreamsign for me), firstly, I count my fingers, most of the time I have about 6 (though one time 18), then I look to see if my hands look right, I have some strange skin thing on my lidt hand, it just means it has a tiny red dot that I can't get rd of, anyway, I check for that, see if it's in the right place etc. If it all looks right, as a last check I try and put my right index finger through my left palm.