David, I design the graphics on my computer after drawing the airframe complete in two dimensions. Once the dimensions of the model airplane is drawn I can make the trim scheme look pretty much like it will when it is applied.
I use Corel.
Our airplanes are three dimensional so sometimes it takes more that one try to get the design to wrap around a surface that is not flat, most are not! If I'm copying a real airplane, like Chip Maroney's Super Chipmunk, I paste the .jpg image onto the workspace in Corel and copy away. Our models don't look anything like the real thing in most cases some artistic license is granted.
Mac Tac is the preferred masking material in the Northwest. It is vinyl and paint will not stick to it. I buy it from Ordway, a dealer in L. A. and the will cut it to any width. My cutter is only 14 inches wide but is plenty big to do any design I've wanted to do, including Paul's original Predator, although I didn't to the artwork only converted it to something I could use and cut the mask.
Yes, you sick it on the surface and paint away. Not quite that easy! The mask material has a backing paper that removes easily. Transfer tape is applied to mask and the backing is removed revealing the sticky side of the Mac Tac. On the more complicated designs I prefer to use Windex on the surface so I can move the mask around to where I want it. There are a lot of tricks to getting things lined up, registers cut into the mask is one of them. Like the Rare Bear nose art.
Going around compound surfaces can present a problem also. A little heat and a lot of patience helps.
Lanny used one of my masks for his airplane. He only wanted a name and AMA number, pretty easy.
As far a plane I hate to fly, I still have one, sort of. The Bearcat was just plain to heavy. I didn't fly it so I couldn't hate it
The Freedom 45 I had at VSC last March fills the bill, although I don't really hate it. It is just very difficult to fly. There is very little margin for error and in any turbulence it becomes a real handful.