Bottom line: Learn position. I don't think I even heard position mentioned in the above lists.
Also
equity. I've read huge discussions on some threads by people who didn't even know what equity is.
Stop the snap calls, raises, folds, etc.
I did like the mention of preflop all ins.
In a lot of cases that's the only way to go. Shove or fold, but some of the BS hands that go down preflop you've got to wonder how much they've been drinking while playing.
But the adding all this together leads to what I see people fail at the most which is the ability to play a deep stack.
You're sitting in 1st place with 2x to 4x the average chip stack. Don't call a bunch of all ins just because you can afford it.
Consider equity.
Okay, I'm tired and rambling.
Have a good night people.