I generally aim to level the crafters together, but since one of the things I'm doing is making my own DoH/DoL gear, weaver tends to pull ahead of the others, especially in the early levels. Then I use leves and/or Ixal quests to focus on whichever is falling behind and try to get them back in sync with each other, or at least close. The one I most often fall behind on is culinarian, just because it takes longer to do all the gathering for it since it's recipes tend to require more raw materials than the others. (Though to somewhat balance that out, CUL requires less intermediate crafting than the others, like how WVR turns fibers into thread in order to turn thread into cloth in order to turn cloth into gear.)

(My main has already had them all at 50 —my level cap— for a while now, but I also craft on a couple of my alts and am still leveling those.)