So /vp/, I want to into competitive but I have no real clue about double battles, there are so many variables I don't really consider in singles that seem to do wonders in doubles. Has doubles changed at all for gen 6?

What kind of strategies are common? What are things that need to be countered? Are entry hazards as common and damning as I think they are? What kind of teams/strategies are you using this gen?

Basically, double battle thread.