Well, i have a ton of ess, and i'm not sure which to runecraft, airs or earths, or fires, i'm not selling these, so prices don't matter. I mainly want the rc xp, but which to use, i'll get more from airs, but i'll get more xp from earths/fires. Which should i do?

do FFA

FFA? what's that, i don't know the acronyms of runescape.

Fast Free Airs? world 16. you will only be able to do this untill january when the new updates come in.

Best you can craft. For the exp.

Yep, craft the highest you can :

Try making a mix of air runes(to get the money you spent on ess back) and the rest on fire/body runes.That should get you both runecrafting xp and the money invested back.