There are no rules for good photographs, there are only good photographs.
- Ansel Adams
To me this thought is really important. Too many photographers spend too much time worrying about rules. The only purpose the rules serve for me is as an analytical tool for when I cannot work out why something didn’t work. If I have an idea for a photograph that I think will work and it fails I may try to fathom out which compositional rules could help me solve the problem the next time out.
Seriously though, if you think having the tic-tac-toe grid visible on your viewfinder or viewscreen, so that you can get the rule of thirds working, when you take the shot is going to improve your photography I think that you are probably in for a very big disappointment.