Pretty sure I've mentioned this on another thread, but one of the best ways to help out your alliance is to create an account for sending tanks.
You only need level 4 for the UU French/Greek tank to be "alright" for most of your alliance members, unless they're high atomic. Once you reach level 10, as we recently did, those tanks are beyond formidable. I do play on the account in the meantime, starting upgrades and raiding, but even making one solely to log in and donate tanks is tremendously helpful. Or artillery, if you're into that.