Best way to earn BP?

Still fairly new to the battle frontier and notice that in addition to the "power" items there are some other things that can only be gotten with BP. I was wondering what everyone's opinion was for the easiest, quickest, or best way to earn BP

it all depends on the type of trainer you are to awnser these questions:
i like doing it on wifi, if your not the best battler, you can hook up with a good battler, and they can help you win, and as long as it doesn't disconnect you, you still get the battle points
if you don't have wifi i suggest that you go to the battle tower, the middle lady, it's pokemon are not fully evolved, and all the pokemon pokemon are lowered to lv. 50(so make sure you pokemon are lv. 50 and above), it's probably the easiest place to get battle points

Monkey