Open Earned Chests at Night
In addition to free chests we also earn multiple different types of chests from multiplayer battles. Regular chests, epics, magical chests, or even a Supermagical and Legendary chest. These take 3, 8, 12 or even 24 hours to unlock. The game will also hold for of them for you.
Meaning once the four chest slots at the bottom of the screen are filled, stop playing, or pay to unlock one. Otherwise you're literally missing out on rewards, and might miss a better chest in the rewards cycle. I just earned a Legendary chest from a battle, and a magical. I plan to get one started, and save the Legendary in the hopes I get the new legendary card coming soon.
Make sure you always have at least one slot open when doing battles, or else when you win you just won't get any award. Throwing away gold, gems and new troops. Additionally, make sure a chest is currently on the clock being unlocked at all times.
I open the small 3-hour chests throughout the day, and start Gold 8-hour chests at night. That way in the morning I wake up to three chests. Two free ones, and a gold or magical chest. Clear those, and throughout the rest of the day the game can be unlocking another, or earning two more free chests. It's a never ending cycle that's crucial to game development and progress.