lol, wish you were in my server, would be much easier :P i could show you instead etc :P

well, i found doing the gc leves "protect this and that" works very well. Just remember to cast protect and stonewall on the guy you protect, let enemies come, attack one at a time, if it comes more, dont aggro them, they automatically go for the guy youre protecting, dont care about "wasted seals", i am in limsa grand company, so i did my 25+ leves in cassiopeia. Myself im at the bald knolll one, 40+ atm, but its the same thing, im getting around 600-800 exp per enemy, im also getting seals and im getting exp for finishing the leve. Also, failing the leve aint the end of the world, you lose a bit, but you earn a bit too

Theres also gc leves like "kill as many enemies as you can in x minutes" all these enemies gives you great exp, just remember to use the guardian buff. In one of those, i got 30k exp in 15 minutes earlier