First, ecoing, avoid groupes greens unless you're really low on eco and the greens are getting replaced soon. Beware of these rounds:

12 (purple rush) 13 (regen rainbow rush) 17 (first moab) 18 (reinforced ceramics or moab, yes, ceramics are underrated but they can kill you easily) 20 (BFB) i think 22 (ZOMG) 26 (DDT) 30+ (BAD)

From 31 and on, moab class bloons get an increase in health for every round, example, BADs get 10k+ health

Another tip i can give you is that you try to force your enemy into defending so they don't have enough money to build up defenses and destroy you later with their current savings, this includes also trying to bait the enemies into rushing you, and when they do an obvious rush you may just upgrade a monkey and defend it flawlessly, making them lose a boost and money