You have to expect to have control. Let go of common sense and previous conceptions about how people, physics, etc. This can be a tricky thing to do, as you've never really lived in a world where you have complete control over everything.
As stated, control accompanies practice. Start off small, try flying, lifting something with telekinesis, or using mind control on one DC.
After a while, move onto doing more interesting things like making beautiful people out of fire and having sex with them while riding on a magic carpet and shooting UV lasers at giant dragon-eurypterid hybrids that you are controlling (this last suggestion may take time to master).