PSP has many features. Take some time to learn the program.
If you are just "playing around" with skinning as practice in order to develop better techniques then ok. But as is there will be a limited number of skins per plane (15). So these will need to be top quality.
Right now there are very few folks who are making skins that are "good" enough to make it. So if you are serious about learning how to make good skins you will need to spend some time learning how to master PSP.
There are plenty of tutorials and sites that help with techniques.
I am not saying I am an expert. In fact I am still learning myself.
Here's an example of my current project: (I have an updated version based on some suggestions fester and others have offered its just not quite ready...)
The first thing I would suggest is enlarging the image to 1024 x1024 or higher, find a good set of 3-view drawing and take the time to do a template. This is the most time consuming part but once you get a good template you can use it over and over doing different paint schemes.
Be advised though all the planes that are currently 256 x 256 will be re-done to 1024 x 1024. There may in fact be some changes in the model and changes to the textures. A skin you redo from 256 x 256 to 1024 x 1024 may not work right.
Also I would stay away from checkers and the like because a lot of the AH textures are stretched or mirrored. You will run into all kinds of headaches trying to get them right. In most cases you wont be able to find a fix.
Check out Fester P40E thread. There are a lot of useful tips.
Good luck...
