go fight the elite four and beat them over and over and you will reach a 100 soon i did this myself and it worked
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Trade them to another Gameboy/ds you get one and a half time the xp then trade them back, notice Gameboy shows you how long ago i did it ;)
Easy play well
There is an easy way to get your Pokemon to a certain level. All you need to do is collect rare candy and use it on the Pokemon you want to level. This will automatically level up your Pokemon.
keep battling Pokemon and people
Try using Rare Candies for easy levelling. :)
if you mean what Pokemon are easy to train, the easiest Pokemon to level up and stuff is your starter Pokemon. it's the same with Ruby and Sapphire, the start Pokemon always seems to level up quicker than caught Pokemon (at the beginning anyway) hope that helped :3 *Shi ~
fight the elite four
Give them rare candies which increase a pokemons level by one.
its easy all you need to do is just level up a snorunt to level 42
Easy. Give him or her an Experience Share, then battle a high level pokemon.
Easy way to do this is to give it the item exp share then use your stronger Pokemon to defeat trainers your wingull soon will level up and evolve.
well it easy really there two ways to level up Buneary you can put him in battle and level her up or you can find a rare candy that level up by one for one pokemon.
Golden seeds: they level your Pokemon up by five levels each time they eat one.