Orange peel is an irregular or bumpy surface in a sprayed finish caused by spraying a liquid that is too viscous, or thick, with too little air pressure, or by moving the spray gun too fast or holding it too far from the surface.
When defined in this manner, the methods for avoiding orange peel are obvious.
To reduce or eliminate orange peel, thin the finish or increase air pressure (or both). If you’re using a turbine rather than compressor, you can’t increase air pressure. So thin the finish.
Also, arrange lights so you can see how the spray wets the surface in a reflection as you’re spraying. Adjust your speed and distance so you are spraying an evenly wet coat.