I was talking to a student from the mentor thread today and I remembered something I did a long time ago that REALLY helped me improve my play.

When you play a ranked game, have notepad open. Every time you die in game, alt-tab, open the notepad and write down on the line why you died and what you should have done differently.

"I went aggressive level 5 and died to Xin. I should not have went aggressive when I did not have my lane warded."

Something like that. Just a quick little line and then go back to game in time for your respawn.

After 20 games you will start to see a few trends in where you mess up. You can then visually see where some of your key problems arises from and can then take measures to fixing/improving your play.

I hope this little habit will come to use for someone.

EDIT: So two things.

First, TIL /n

Second, yes, some deaths are acceptable, but the majority were preventable, and, even in a situation where your death was acceptable, there is ALWAYS a way to improve on what you did. There is ALWAYS a better option, or better positioning, or something. However, I mostly meant mistakes early on here or screw ups in teamfights. No deaths before late game teamfights are really ideal, and no deaths that were not in a 5v5 or 4v4 fight late game are acceptable. Really, at most you should have 1-2 deaths a game. If you have more then that, then yes, you could have improved your play.