Know what is going to happen.
I find that if you put a little effort into it, especially in the early game, you should probably know every move that is going to be made. Not just in your area, every move. If you don't, then maybe the moves are going to be against you. Later, knowing moves becomes even more important, because it allows you to stab with the utmost effectiveness, missing planned bounces and catching people out of position.
Also, I find in higher level play I fight my allies as much as my enemies. Jossling for position, but still talking in concert. I took Rumania from you because me not having it is detrimental to the long term prospects of our alliance, etc etc. You can't take these things personally.
As far as research goes, some guys swear by it. I have only ever used it to point out to a third party a tendency as a reason to ally with me.
With proper diplomacy and reads, you should never be in the first two eliminated at least. If you are in the first two, you have almost certainly done something terribly wrong. Not getting killed should come quite easily after you have the diplomacy down. Winning is of course much more difficult.
Tactics imo are of little importance, because almost anyone can get a good grasp on them, and sometimes the best move is the one they are expecting.