I don't know what's the most common marking system for the rest/free strokes. I think in printed sheet music commonly left hang fingering is marked, and sometimes, at difficult spots, there's some reference to the right hand configuration, but usually no apoyando/tirando marking.
I tell you about the simple markings I use in my sheet music. When I was a beginner, I liked to mark everything for myself in the sheet music (in pencil of course) to facilitate learning and lest I forget the fingering I'd memorized. Now, having more experience, I don't scribe so many things in the printed music any more, but sometimes still mark the the apoyando or tirando stroke, at a critical place or when a special setup is needed. In these places I mark the apoyando with an a/m/i/p underlined, and the tirando with a/m/i/p with a dot underneath (or nothing). I think it's a fast, effective and easy-to-remember system. The marking can easily be deleted with an eraser and corrected, if you happen to change your mind.