Trick 2: Start off with buying wooden chests and buy until the last card is 3 stars or more. Then move to the golden chest and continue buying until the last card is 4 stars or golden. Then start buying magical chests until the last card is golden. After this step, start over and repeat.
Trick 3: Buy 20 chests of each type. Example: 20 wooden, 20 gold and 20 magical.
Trick 4: When reaching a new level, build all your village objects to 2 stars each. Then start buying chests.