I know you didn't just compare tren with anavar. (Not picking on you, but I don't know how that comparison can be made outside nutrient partitioning abilities.)
OP: Depending on the quality of the anavar, I'd start at 50mg ED and stay there for a week. If you don't start to see big differences (unfortunately pumps are one of the big indicators) in vascularity and strength, I'd bump it up to 75mg and then 100mg a week after that if you still aren't satisfied.
Just remember; anavar pumps are notorious for a reason. If you've never had a calf pump while driving on the highway or an abdominal pump while doing tricep push-downs/deadlifts, you're in for one hell of a treat lol.