If all doors are a similar dimension I've run 2 - 2x4"s parallel about the sawhorses spaced just broader then the doors. Put complete nails in the best and bottoms of the doors hold them to the 2x4's buy the nails and paint a single facet then flip. Utilize primer http://edwinifbyr.webbuzzfeed.com/1772394/the-greatest-guide-to-get-grease-put-of-painted-kitchen-cabinets