Pokemon Black Message Board  

what is the best way for me to train my pokemon they are all level 20

Just keep battling other trainers, there should be plenty around to help you level up. If you have battled them all, you should be pretty strong, but otherwise the grassy areas are the next best thing with battling wild Pokemon, and it all depends on where you are up to in the game.

Go genocide all the Audinos in the game. They give away mass amounts of experience. It's ridiculous. Just walk around next to a grassy section until you see a shaking spot of grass. Chances are, it's an Audino. They appear on literally every route, so you can do it anywhere. The higher the level they are, the more experience you get. So go somewhere with higher level pokemon.

I just concentrated on one pokemon, so in the storyline I got it from lvl 3 to lvl 65 with just the storyline.

That storyline was pretty straight-forward unlike the others... Anyway, if you go to Nimbasa city and go in the different sports arenas, the player's Pokemon level up with yours. Pretty easy way to gain quite a lot of Exp. Points, especially since there are a couple double-battles.

Not true they only go up level 67 at the highest, but it's still a great place to train I've been doing it for months and I have a decent amount of teams that I can put together.

Yeah, if you're far enough in the game you can train quite a bit. I start with the sports arenas and when I'm done with them I go to Black City and battle those trainers. Then I go to Castelia City and get on the cruise ship and battle the trainers on there. Also, Cheren is in the last chamber of Victory Road, so you can also battle him once a day. Once all of those run out, I battle the Elite Four.