This is assuming near max TH8 Troops (Preferably maxed)
GoWiPe - Good 'all rounder' sometimes works better on bases with a bigger core Hogs - Great for compact bases, try to locate big bombs and set them off before deploying mass hogs Balloonion - Great against bases with lower level air defence Mass Drags - Best against exposed/spread out air defence and wizard towers
Max troop levels at TH8 for these strategies:
Golem - 2
Wizard - 5
P.E.K.K.A - 3
Hog - 4
Balloon - 5
Minion - 4
Dragon - 3
Try all of them and see which you are most comfortable with. I for example know that I should be using GoWiWi against certain bases but I still use loonion/lavaloonion because I am most comfortable with that strategy and use it so much I can use it better than others out of practice would be able to, also I love it, it's my favourite strategy.
Find a strategy you enjoy and get better with it, or a couple and change army depending on opponents base.
Finally don't forget to request for CC troops that will benefit your army composition the most, best to ask for whatever your lowest level troop is to balance out with stronger versions of themselves, but in some cases a different troop may be more beneficial.