how does a pressure affinity fly?

We know from the short story that you can become a thunder bringer by a combination of force, wind and pressure affinities, instead of the classic/more normal force wind and gravity combination.

But how does a pressure mage fly? Do they make high pressure zones beneath them, releasing them to let them explode forward?

Or do they create low pressure in front off them, like wind mages?

Or some third way