Well,if you have troop capacity of 200,that should be on TH8 (if you are not hopper)and you have unlocked pekka and valk..its very easy to 3 star any base.....Just train 3 Pekkas, 7 Valks, 15 Wiz and the extra spave which is left..I take 3 archers and 3 Wall breakers..As for spells, I take 2 healing, 1 rage and 1 earthquake... I prefer leaving all troops at one spot....For spell first healing then rage then healing.If done with strategy and patience... 3 star is the only thing you get..