tips for a 900 points blitz gamer

Follow opening principals and practice basic tactical patterns fork, pin, removing the defending, and discovered attack.
After your opponent moves, find the new squares that piece influences, and look for what it threatens.
Calculate forcing moves non-stop.
If your opponent isn't threatening to win something, and you can't win something, then keep your pieces active. Rooks on open files, bishops on long diagonals not blocked by your own pawns, knights on outposts.
Most of the game will be looking for your opponent's threat, and then calculating forcing moves for yourself.