i recommend the restaurant near lake valor
use the exp share
easiest way to train your Pokemon is by batteling each trainers or you can practice with wild Pokemon in the grass,cave,or sea
The easiest way is to use the Poke'Radar.
The easiest way is just buy a r4.
Get an Action Replay and select 100% Pokemon on pokedex.
You can use an action replay, its the easiest way.
To get a thunder stone, or any type of stone on Pokemon pearl, you need to go underground and look for a bit, I found this the easiest way to get stones.
you cant get it in game. easiest way is to trade from heart gold or soulsilver
use a action replay code run any where
Mostly the 2 only level upers: Rare Candies and battling stronger Pokemon with your defensive.
the easiest way to train strength would be the Soul Wars minigame.
you can't capture it in soulsilver but you can trade it from pearl,diamond,or platinum