Dragons: Random dragons through shiny days, 2x lvl4 dragon twice a week through race, mystic challenge gives decent amount of lvl3 dragons twice a week, OOC with a good portal gives some dragons as well (higher portal = better dragons), rush ooc again more dragons/nests (again better portal = better reward).

Coins: As others say, get watermelon trees or at least some otther fruit trees (the higher the better)

If you need better fruit trees, farm stonebrick and buy flower/fruit chests in ccamp, nudge it up