How does one improve in Blitz?

After returning to Chess a few months ago after a year hiatus, I'm curious as to how one improves their Blitz game? I've been able to improve in long games (IE 30+ Min games), but I've struggled to improve in Blitz, and with a Blitz tournament coming up, I'd like to try and train a bit.

Any suggestions? 

AnonymousP, playing long game is good but analysis it is even better.  Then you will know why the move was made.  Have better understanding of the position.  That is how i improved my bullet.  But these things take time.  Anyway, you also can do tactics at here or chess tempo.

The way to improve at blitz is the same as the way to improve in classical time controls: Study tactics tactics tactics, work on your endgame, and practice at the time control you want to excel in.