Digging in the mine can yield up to 10 diamonds daily.

Keep an eye on the Event Board to see when these are coming up so you can prep your barn. 2. Farm "Diamonds" for Free

Catching new fish types can earn you hundreds of diamonds over time.

Check your house's achievement board; completing them is a steady source of premium currency. 3. Claim Official Supercell Freebies

Sometimes the developers give away massive amounts of coins directly.