where and when?

[Satori]

I have checked these boards and cant seem to find anything usefull,

I know from like level 11- 20 its the dunes and 20-26ish its quiffum but I havent a clue whats next or for what level ranges. if somebody could let me know what most people do it would be great,

[Murphie]

http://campsitarus.blogspot.com/

Have at it.^^

[Caspian]

As for whats the most popular, its the Jungles (yuhtunga and yhoator), just be sure you get your pass for the airship there.
31+ GC is the most popular. For the most part if you're looking to sit somewhere and wait for an invite, then that's the level where you can just start hanging out in Jeuno if you don't wanna do anything while LFP. And really GC is great and all, but I partied in other random places during those same levels with the same or better results.
If you're looking to make your own parties, then use Murphie's link. Be creative and always search the zone before heading out there. Just to be sure there aren't 8 other parties with the exact same idea.
If you're looking to just join someone else's party, then LFP in Jeuno all the time, or in Kazham for the jungle levels and Jeuno at all other times.

[Mhurron]

Get invites and follow your parties. Just remember where you went for the next time you go through.
Though at lvl25 most go to the Jungles outside of Kazham and to get there you'll have to do a little quest first.

[Intensity]

I prefer to skip Garlaige Citadel after the jungle and instead go to Eastern Altepa Desert. Usually much less crowded.