If you are thinking of competing, let me give you some tips that I wish someone gave me 
Ucla/dator method:
We use all of the same color to charge mana at the same time
Stages 1-5
-combos are key on these. The higher scores will result with the higher the combos in the fewest moves. You also need to have those combos in the color you brought to charge your mana. The ideal is one move resulting with a 5+ combo charging all your fast mana. This is why you see all the top placers fleeing! Boards like that are hard to find.
6-10 have multiple bosses so they can’t be killed with items alone. These we look for a way to make a diamond within the first move and knock down the first two stages with items. Save the diamond for the bosses. Mana up your shield downs and hope the tiles kill the bosses.
10 we may be unique but I use wu because I need that tile damage to knock out the bosses in as few moves as possible. It is a risk but with great reward.