More pressure

James,
no simple answer for this problem . Way to many variables. increasing pressure, increasing amount of solvent. using slower solvent. slower catalyst , holding the gun closer to the surface, narrow the fan adjustment down slightly, your gun traverse speed slowed down. these are all things that can and do effect how the clear lays out.
what gun are you spraying with?
what air pressure at the gun,
what type of urethane clear
what solvent
how far are you holding the gun away from the surface
I am more than willing to help, I paint profesionally so I know some of the things.

The biggest thing is getting the gun tuned right, just like getting a good stunt run,, it takes experience. Most of all don't get frustrated, there are no magic answers and to imply that any ONE thing is right is simply not realistic. Now if only I could get my motors to run as well as my SATA sprays, I would be in heaven!

FWIW, I sprayed my Oriental most recently, I use a SATA mini jet, with about 45 PSI line pressure. I use PPG 2042 clear with standard catalyst. The mix stated in the factory specs is 4 parts clear, 1 part catalyst and 1 part reducer. I spray with a 4 to 1 to 2 mix, an extra part of solvent which helps the clear get from the gun to the surface with enough viscosity to flow when it gets there. The Sata atomizes so well to use less solvent allows it to dry to much on the way from the tip to surface. The Sata has a fantastic pattern for a detail gun, about 4 inches wide. However I generally neck it down to about 3 or slightly over 3 inches for better control and overlap control.
Personally when painting my airplanes, I use the reducer that is one step slower than recommended for the same reasons. for example, if the tem calls for DT 885 I will use DT 895 which is the slower (higher temp) reducer. Again this allows the clear more time to flow. My Oriental has not been buffed and there is no orange peal or texture on the clear at all. The only buffing needed would be to remove a couple small dirt particles that found their way in. I don't like buffing clear especially on something that lives in the harsh chemical environment of our models. there is a certain resilience that is removed when you polish Urethane clear. IOW it weakens it to some extent.
For the record, I must state that in my opinion and experience, using any solvent other than what is designed for the product you are using is asking for disaster. Yes some people do it all the time,and get away with it. Keep in mind that paint companies have engineers and product developement people that spend years formulating this product to work consistantly and correctly. I think its pretty out of the box to say that we know more than the guys who engineered this product and spent all this time and money testing it. I do understand why some people do what they do, but I strongly disagree with recommending that someone else do it.