Give them rare candies which increase a pokemons level by one.
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
Easy. Give him or her an Experience Share, then battle a high level pokemon.
well u could train alot or
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.
the easiest way to level up your Pokemon to put it in daycare Pokemon will level up soon.Trade the Pokemon to friend and have it hold a lucky egg it will level up quickly.
there is no easy way to get to level 100 just stock up on joy seeds until you have enough for all your pokemon or just the pokemon you want to be at level 100.
Easy play well
The easiest way to level up is to feed Pokemon Rare candies.
a easier way of leveling up is below! Pokemon level 1-30 find a level 50 Pokemon Pokemon level 31-100 find a level 100 Pokemon Pokemon level 101-200 fight a level 200 Pokemon Pokemon level 201-300 fight a level 300 Pokemon and so on... WARNING YOU MUST DO THIS ON VERY EASY!!
Battle the Elete Four over and over again and eventually your Pokémon will get to lv. 100.
The fastest way I know is Exp. share. A really easy way is to put your highest level Pokemon in front and give the Exp. share to a weak Pokemon (Level 1-25). Go to Victory Road (fly to Indigo Plateau) and defeat as many Pokemon as possible. Another way for higher-leveled Pokemon is to defeat as many people as possible using the Vs. seeker. You put it in front and find an area with Pokemon around the same level (or weaker). That should work.