Third: Turn tracers OFF. They do not help. They hurt.
This is a generalisation I can not let stand uncommented.
It varies much from player to player. Many players do benefit from turning off tracers, but also there are some (many? most?) that do suffer. For example myself.
At various points in my career, from being barely able to hit at all to being the good shot I am now (shameless chesthumping, yes i know) I did try to fight without tracers.
Unlike many other pilots, I was doing fine at first. But after 1-2 days, my aim started to suffer. My hit% started to drop. Slowly first, but then faster and faster until basically being halved after 5-6 days. This was each time I tried it, four attempts total, each about a week long. I would really like to fly without tracers, for it has some advantages, but it just doesn't work for me in the long run.
It seems that I need the constant visual feedback to keep my feeling for the ballistics & proper angles.