Speed

Speed is an important aspect of Blitz.  With only 1 minute, you need to move fast to get a lot of multipliers and to get BLAZING SPEED.  So as soon as you spot a gem, move it, but keep an eye out for another one or two possible moves.  You need to spot a few different possible moves across the board from the move you're making, so that the gems nearby don't shift and screw up your future moves.  I look for a few different moves just in case a star or flame gem explodes and screw up one of your next moves.  Always have backups just in case.