1. At low levels, if you're not starting with HQ mats, then you will have to rely on luck. Tricks of the Trade from ALC and Hasty Touch from CUL will be your best friends (or worse enemy, in the case of Hasty Touch) all the way up to the top tiers of crafting. There are no set rotations, but the idea is to open with Inner Quiet and use Tricks of the Trade whenever possible and use the CP gained to restore or extend durability through Master's Mend (II), Waste Not from LTW, or Manipulation from GSM. Finish up with Careful Synthesis from WVR or Rumination from CRP and then spam Synthesis skills. The other cross-class skills become useful later down the line (e.g. Ingenuity for 1 and 2 stars).

Every "rotation" you see at end game crafting is built around this idea of regaining CP and restoring durability, so play around and get familiar with it.

2. HQ gear will always be preferable, but if you can't afford it, NQ works to. Once you hit level 50, HQ gear is mandatory.

3. Look at what you can make, look through the market board for them, one by one, look at how much it costs you to make those items, and do profit calculations.