Create full-screen transitions
While at the beginning of the transition, move the incoming screen somewhere outside the device area. You can move it below the device area to create a slide up transition, or place it to the right to create a push left transition.
Try placing the incoming screen directly on top of the outgoing screen and change the opacity of the incoming screen to 0%. This will create a fade-in effect. Try scaling the incoming screen slightly. Go to the end of the transition and try moving the outgoing screen.
In playing with various techniques like this you'll quickly realize the power of the Transition Designer.