Dreamdale Rainbow crystals, wool, and Octocoins

Dreamdale Fairy Adventure: Best way to mine for rainbow crystals:

Best and only way is normal dungeon runs try to pick up every shell you see to trade for gems as well but dungeons are definitely the fastest. i think other than those two, the only other way to get gems naturally is through the ranger and his raids every few hours.
2 free 5 diamonds videos daily.
Season events like Production season gives you 30.

Dreamdale way to get the wool faster:
You can ride a pet (watching an ad, using a ticket or buy vip for a permanent pet. You can get them for doing quests for this yellow guy, sometimes you are lucky and dig them out of these treasure stars, or you can earn them in the seasonal event.

Build a factory on the main island.
Image is given below.

How to get octocoins?
Through quests from the villager by the bridge.