Easy 3 steps:

Elevate - Attach 2 spacers to the bottom corners of each doors. 
4 spacers per pair.

Connect - With doors sitting at
90-degree angle, push pin down until it is tight.

Paint - Line up all doors in a row
and spray.

 Tips:

Mask hinges and cut top off for pin to be inserted.

 Or swap out the hinges with older hinges that can be painted. 

Both sides of the hinge stand can be used to link a left or right door.
Use left and right doors together or pair 2 left/right doors.

For heavy or tall doors, use 2 hinge stands per pair.