I use Dewalt Tstak components. You can purchase different pieces and clip them all together to make it however you want it. I also bought the foam insert and custom fit it for my chargers so that they aren't banging around.
I have a shoe container for all my unopened parts. Then once opened the spare parts end up in those Plano storage trays.
I also use the little containers they ship bearing and screw kits in, they are perfect for holding bearings, screws(obviously) and electrical connectors.
I have some of the plastic cases that servos come in but not sure what to store in them yet.
Also save all the tiny zip lock bags, they can come in handy too. I like to keep things like shims, washers, orings, and e clips in them, these things can be a pain to try and grab out of the Plano trays.