All I can to is tip the balance of my dreams to make it so it's a good dream, but I can never do anything completely amazing. Like one night, I was attacking this kid who was totally evil. He was winning, until I made myself a hammer. I smashed him to bits, but he still moved. I couldn't make him go away. I tried closing my eyes and manipulating, but he bit me when my eyes were closed. After a while, I smashed him till he was a pulp, then continued with my dream, however, it would be nice if I could do something like materialize a friend, fly, time travel, the bigger stuff.

TL;DR: I can only make a dream that sucks into a dream that's alright.