I have just purchased a flash and after the first week I purchased a cactus wireless trigger, stand and umbrella. (Jumping in head first)

My question is how much flash do you need? Should I have lowered the flash and keep the natural light stronger or the other way. This is my first attempt to try and balance.
I have posted an example one with and one without.

Info Flash was 90 deg to the subject and the window was opposite about the same angle with a reflector out front
Nat.jpgNat-2.jpg

Thanks