What is an underrated action or item that doesn't require money that you learned late into playing this game?

I'm just looking for ways to progress further in this game without spending real money if that can be avoided. I'm currently a pretty strong level 28 and have spent maybe 20 dollars over the course of 438 days of login.

I'll give my anecdote: I didn't realize that you could dismantle drone parts and use them for upgrades until 100-200 days ago.

Thanks, everyone!

Edit: I was incorrect. I meant dismantle hero accessories (gear), not drone parts.