The ladder is not the best place to test out your full capabilities, and here are several reasons why:
1. The best players are usually those who are "voiced" in the Smogon Doubles chatroom, and they don't like to ladder for the sake of time. Of course, there are some exceptions.
2. You know the ladder is a joke when someone rampage to Rank #1 with Mega Pinsir or Rank #2 with non-TR Mega Mawile team.
If you truly want to test out your capabilities, then you can always join official tournaments or to a smaller extent Tournaments hosted within the Smogon Doubles chatroom. On the matter on how you could play better, we can not exactly specify unless you tell us what your problems tend to be. Again, you're always free to ask around the Smogon Doubles chatroom for more advice.