New research at Smogon reveals that , unlike previously speculated, using the Masuda Method while having the Shiny Charm does increase the shiny chance, upping it to about 1:400 (Source, if it means anything).
Unfortunately I can't get the Shiny Charm until bank comes out. ;-; Though it's back out in Japan.
Also the best place to level anything is Restaurant Le-Wow but it's more of a late game thing, and since you're trying to level a Ralts you're probably not there yet. =P Other than that I occasionally use the Battle Chateau to level things. The trainers there won't be the strongest at the beginning but their levels increase as you battle them.