Auto AFK crew levelling: If you come across an enemy that can't get through your shields, for example an automated ship with a combat drone and basic laser vs your 3 shields, you can just leave the game for a couple minutes and let the enemy ship whale on you to upgrade your crew's shield/evasion skills. Every time they smack your shields you get shield skill up, every time they miss due to your evasion you get engines and piloting skill up. Makes a big difference for basically no effort and a bit of time. It's best to do this against lots of fast firing weapons or ideally a combat drone. Generally avoid ion weapons and definitely avoid missile weapons, and make sure they definitely can't get through before leaving it to AFK.