Is it a rule of thumb that as soon as you get a new recipe you level off of that? Or at some point does the amount of "XP" you get per number of materials needed to craft shrink and you are better off leveling lower level recipes? Has anyone done that math?
Did some testing.
At some levels, its actually more efficient to level an older recipe, even though you've unlocked a new one. I tested by making a recipe that requires 3 dusk orchid bundles, and another that required 5 (and was higher level). Yes, the higher level recipe gave more experience, but in terms of time efficiency, the recipe that calls for 3 bundles wins out. So, be mindful of material requirements when you're focused on leveling Alchemy as fast as you can.