Give it lots of berries that raise happiness but lower stats. (like attack, defence, speed, etc..) Give it massages at veilstone and at the resort area. And give it things like proteins, carbos, etc.. You can also use it to fight alot.
Get 50 Pokemon...
the quickest way is probably to get to the elite four and beat them over and over with exp. share on the Pokemon you want to level up
use the action replay cheat.
Have a Pokemon that was traded to you then have the Pokemon hold a lucky egg and start battling your Pokemon will level up very quickly.
use dig
trade your starter for a cyndaquil and smash their face in
the quickest way to lv. up your Pokemon is...first,get a rare candy (you only find them in poke balls around the game. or by an event if their is one)next,once you have one go to bag then press A on rare the candy.then, press A on the Pokemon you wont to lv. up.finally,POOF!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! (YOUR)Pokemon will be up ONE!!! LV.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!THE END!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The quickest and easiest way to beat them is easy: 1. Use a good combo of dark and electric Pokemon. 2. Focus your attacks on Solrock, after KO, finish off Lunatone.
give your Pokemon some rare candy
Travel with it and give it a soothe bell, and have the massage person massage it and eventually it will be happy
Pokemon that evolve with stones
he has these Pokemon: lvl18:bayleaf lvl15:gastly and another but can't get to it if you chose totodile