As with all match-3 games, be on the look out for lines of 4 and 5 which can cause some major shifts on the board.
Power-ups
Power-ups can save your bacon, so spend a little time collecting them on levels you are about to complete if you have time to spare.
Timer
Keep an eye on the timer on each level. There is very little warning to when you run out of time, so if it looks like you are not going to make it, don’t be afraid to restart a level.