Sell old modules and equipment from tanks you no longer use.
Click Depot –> Modules/Equipment –> Select the Guns, Turrets, Radio ect you no longer use and sell. If you bought these during the 50% remember you are not losing money.
Sell consumables and shells you don't use.
Click Depot –> Consumables/Shells –> Select the Modules and Shells you don't use sell
Sell Tech Tree Tanks you no longer use. I know some people want to hold on to tanks. But if you have not played it in the past 6 months. Are you going to start now?
Have any left over Rental Tanks from events? Sell them and get the Ammo Value!
Sell Premium tanks and earn the Credits. When you buy them back you will need to pay a 10% fee but it is a low cost load.
Get those Tier 6 and 8 Stongholds going. You can make almost 1,000,000 credits in 1 hr with a Clan Booster running. Not part of a clan? Maybe its time to join?