How to collect more shadles?

I think you mean shards, there are several ways to earn shards.

1. Complete the TOTS event, upon completing the event under each league, you'll be granted shards and the quantity is also high.
2. Daily activities, once you do this you'll be granted 10 shards per day.
3. Exchange of TOTS players, you can exchange TOTS player fodder for shards.
4. Open the store packs to get TOTS players, which in turn can be used in exchanges. The 3k gem pack seems worthy enough granting you a 103-109 TOTS player.
5. PRAY TO THE EA GODS FOR LUCK