The slow casual way is GC dailies and Challenge logs.

The quick and painful method is old school grind. Run in a square circle and spam buttons. As with all things FF14 Gear is king. If you have up to date, HQ gear you can gather higher levels at 95% add Sharp Vision. The original that uses 50 GP can be used indefinitely thanks to the 10% mining node that you can skip a Sharp Vision on. Mining and Botany, I 'grind HQ'. Meaning I save HQ, vendor NQ and save myself an inventory nightmare. It's bad enough that I have a whole stack of HQ ala mhigan mustard. I certainly don't need the 5 stacks of NQ I will get pushing through those levels.