What is your go-to reality check? That one check you do while having a non-physical experience which NEVER FAILS to trigger an awareness increase.
For myself it's looking at my hands. When I see they're all twisted and not looking like hands, I know immediately I'm non-physical.
Many times in dreams I come to wonder if I am dreaming and I always test it by trying to float off the ground. It always happens if I am in a dream and then from there I gain more lucidity and take over to navigate. But there are times here in the physicals that I wonder if I am dreaming especially if I experience something very exciting, a beautiful scenery during travels, or something out of the ordinary. And when I don't fly upon trying, sometimes I feel disappointed because I am unable to expand my adventure further. But I am still thankful that I get to observe the beauty of the physical plane despite being very limiting.
This reality check was not chosen by me, but rather it arose spontaneously in dreams and now it´s what I use, it makes me laugh. I have several tattoos on my body and I always moisturize them, in dreams I did but...they disappeared, changed places or transformed into other things. It just can't be! I said... it really distressed me. There I realized that I could only be dreaming! On one occasion when I realized I was dreaming, the tattoo turned into a crown... it was fantastic. Now my reality checks in physical are to look at my tattoos and ask myself if I'm dreaming, wait a few seconds and look at them again... in LD they will surely have changed.
The hands also work, I have seen many fingers! (or less) Regarding flying, it was not good for me, since thinking that I was in the physical, and therefore with a conditioned mind, I could not fly, since I didn´t believe it was possible. But I use it when I have gained a lot of lucidity and I "fear" being really physical and I don't dare jump from great heights, lest... :-o