How do I make a character fly?

If you wish to make a character fly, first, decide on a pose.

To change their pose, tap them and then select 'Pose' from the option bar. 

There are some options in the 'Lying', 'Action', and 'Special' categories.  Choose the one that best suits your expectation for the performance of the actor.

Tap the character again.

Then, raise the character up and down by tapping the triangle in the bottom left corner.  

Once you've reached the desired height, use the circular symbol to the right of the triangle to change the angle of their body.  They may be flying like a bird, or diving down, like in this example. 

Then, position the character by switching to the bulls eye movement feature (to the left of the triangle).  

And voila! Previs Pro is the wind beneath your idea's wings!