My favorite things about WW II painting is the vehicles. They're a great change-up from my usual Dark Age painting and I turned to YouTube to learn weathering techniques. The variety of techniques is a bit overwhelming and I'm still learning.
T-34/85: My first tank went together fast. My mistake here was using two washes. After the first wash, I thought the tank looked too bright and after the second, it was too dark! I now prime my Soviet vehicles a lighter green to better show off weathering effects.