I have 4 doors I need to paint. I'd like to paint both sides at once but am having trouble figuring out a good way to hang them so I can do the bodywork and paint. I'd rather make something than buy anything. Any good ideas?

What do you need to paint on the door? just the skin? or the jambs too?

if its just the skins maybe make a frame out of 2x4 angled backwards with another 2x4 across the frame as a lip for the doors to rest on?

I generally finish the inside of the doors (same for trunk lid, hood) first by laying them on a table or bench.
Then I spray the inside of the doors (trunk lid, hood) and all the jambs at the same time. When dry I reassemble and align the doors (trunk, hood) on the car making sure all the gaps are right. You can cover the sills with masking tape or some type of protective material if necessary while installing.
Mask off the gaps by placing masking tape on the inside panel/door edges. Foam tape works real well for this. Then finish the exterior of the car.

I'm doing jambs too. the doors are a different color than the truck. My first thought was to paint the jambs then paint the outside on the truck as '68 Coronet R/T said but I was worried about the masking and overspray.