Here I will be showing you one of my old battle decks(from the 1750-2000 trophy mark):
Level 5 Furnace
Level 5 Valkyrie
Level 6 Wizard
Level 1 Guards
Level 2 Poison
Level 2 Goblin Barrel
Level 2 P.E.K.K.A
Level 2 Skeleton Army
Normally, when starting a match, I put my Furnace in the middle of the Arena, where enemy troops like Giant and Hog Rider will be distracted by it, giving my Crown Towers more time to kill them. Then my play style varies depending on what my opponent does.
If he acts AFK and doesn't do anything, I place a Valkyrie in the back, just to be safe. When the Valkyrie has already reached the Crown Tower, I can be sure the guy is actually AFK and start deploying the really powerful troops like P.E.K.K.A. to get an easy win.
If my opponent is tight on defense, I normally just try to keep chipping away at the Crown Towers with my spells and also deploy troops just for defense. However, once the battle hits double elixir period, I start going on the offensive. I would probably start with a Valkyrie in the back, and my opponent might not be alarmed at first. Then I place a Wizard. After that, when I really want to boost the push, I put the P.E.K.K.A. in the front as a tank. I think it's a good push. The P.E.K.K.A. takes all the incoming hits while the Valkyrie takes out other things like Skeleton Army. The Wizard is mainly used to for his high area DPS and ability to target air. He can easily take out Minion Hordes placed to attack my P.E.K.K.A. and Valkyrie. This combo is very effective. (Also, if I have enough elixir, I will add Guards to the push.
if my opponent is really agressive on offense, I deploy troops for defense depending on what he sends. For example, if he sends a Mini P.E.K.K.A or a Hog Rider, I use Skeleton Army as an effective counter. If he Arrows my Skeleton Army, I would use Guards as a substitue. If he sends a big push like Mini P.E.K.K.A. + Bomber, I would wait for them to cross the bridge, then use a Valkyrie to take out the Bomber. Then I would destroy the Mini P.E.K.K.A. with my Skeleton Army. It all depends on what my opponent does.
I shared this deck to help people from about 1800 trophies to 2200 trophies.
Substitutes for cards you might not have:
Guards ---> Mirror
P.E.K.K.A. ---> Sparky or Mini P.E.K.K.A.
Poison ---> Fireball
Goblin Barrel ---> Miner
Hope it helps!