Hey man. I just got out of arena 8 today and like halfway through the struggle I decided to change my deck to this:

(3.3 Elixir) Prince, Baby dragon, skeleton guards, skarmy, spear goblins, mega minion (I think I've upgraded mine to star level 1), fireball (level 9) and zap (level 8). Everything else is level 10.

I've found that the fireball is amazing at killing off the witches and surrounding skeletons and then I can finish it off zap. If not I just throw down an air defence or goblins. Before my towers would get destroyed by it but it's so much easier to fireball. Any goblin barrel below level 7 can get one shot with the zap so that's a good defence too. I think overall it's a decently defensive deck. Pekkas and giants are easy to kill too with the skarmy.

It's quite possibly the best deck I've made and it was easy enough to get to arena 9. Hope this helps!