Battle-harden motors to prevent magnets inside the motor from getting damaged and binding up during battle
Solder all connections and seal with heat shrink to have strong connections and prevent electrical shorts
Thread lock all bolts and set screws
to prevent loosening from vibration and hard hits in combat
Hot glue wire connections to add strength from hard hits
Repair your chassis with Quicksteel Epoxy Putty between matches to protect electronics
Lots of great information for building your own bot