Cities require resources to buy them. Make extra matches on the resources you need to purchase the next city.
Finishing levels quickly earns you the resource the game determines you need the most. Sweet!
Every 20,000 points gets you an extra life.
Try to link 5 tiles or more to get the maximum amount of points.
Use fully-upgraded power-ups early so you can have time to refill it.That way you can refill it and use it again or save it for the next level.
Don't use power-ups at the end of a level if possible so you can use it in the next round.
If you only have 1 match to finish a level, match as many power-ups as you can and replenish your bonus so you'll have it for the next round
In the harder levels, make matches in the hard to reach corners first.
Hang on to your bonuses during the last levels since there is no bonus round to replenish them.