I see leves mentioned, but not GC supply missions. Check under 'Timer' to see the daily list of your-level craftable goods you can turn in for exp and GC seals. HQ gets you ~twice as much; starred items get you ~twice as much (I've gotten nearly 200k exp turning in HQ starred items at the higher levels). This is actually how I leveled all my DoH at once. Also, if you keep your crafting classes leveled together, you only need one set of gear (not tools obviously) which helps with armory chest space if that is ever a problem for you.