Quote Originally Posted by thebigspendur View Post
I just use the particular DE 3 times in a row daily and then trash the blade and so when I come back to it I know to put a new blade in.
I pretty much do exactly as you described, otherwise I just rely on memory. Sometimes this becomes problematic, as I experiment with how many shaves I get comfortably (or sometimes not so comfortably) from a new type of blade I'm trying out for the first time.