Your best bet for a Garchomp based build is to pair it up with Altaria as that gives each of your dragons + 20 damage. It works well because you have Gabite to search out the Altaria as well as Garchomp but you do need ball power to get the Swablu cards out. Here's a sample deck list;
Well, you're better off just sticking to Garchomp as your main attacker as only dragon types get the boost from Altaria. Blend Energy should be maxed and you want to be running around 13-15 supporter cards as you want to hit one every turn. Pokemon Catcher is a staple trainer which you should be running too.
"Power through ambition." - Overlord Drakow Forum Set