u/I_Throw_What_I_Want

Hey, looking for help about caster positioning..

I am playing a warlock (my second ranged character) but im use to playing hunter where i can move and cast at the same time when it comes to mechanics. Do you just use defensives and face tank? Or is it worth more to move and cancel casting? I feel im loosing a lot of dps running around.. as well as when I level, tanks are running leagues away and I cant stop to cast to do anything..