I made the cupboard frame, so I had to make the doors, too. I took some 1"x2"x8' pine and cut a groove along one egde, cut the pieces to the dimensions of the door, then mitered them. For the center of the door, we used composite board. We painted them to look like the ceiling.
I nailed the boards to the back face of the door, put corner brackets, hinges, and handles on.
Here's the first one in place. I use clamps to hold the door in place and also to put a spacer in at the bottom to show me where the bottom should rest.
The final look.
Jenn's coming up with the cupboard idea did us a major favor. We have a small bedroom, if you haven't noticed. We had our "stuff" jammed all over the place and it was very cramped in here before we renovated. Now we can store extra clothes, camera stuff, whatever in the area above our heads, which otherwise would be entirely wasted.