During the round, I let my Shot Scope keep all the stats for me. I try to keep the number of shots per hole, but I play much better if I forget about it entirely and just concentrate on my next shot.
The stats I pay attention to are FIR and average putts per hole. GIR is (for now) practically an impossiblity, so I don't bother with it except as a curiosity, but I might start paying more attention to it next year if my shots start getting longer. I also pay attention to my longest shots, and my P average - that's just because I enjoy seeing my progress