Measure the shed door opening
Decide on door style and size
Gather materials: lumber, plywood, hinges, screws, latch, weatherstripping, paint or sealant
Cut the frame pieces to size
Assemble the door frame into a rectangle
Add a diagonal brace or Z-brace for support
Attach plywood or boards to the frame
Trim the door edges if needed
Sand all rough edges and surfaces
Prime and paint or seal the door
Install hinges on the door
Position the door in the opening
Mark and attach the hinges to the shed frame
Check that the door swings properly
Install a latch, handle, and lock if needed
Add weatherstripping around the edges
Test the door for fit, alignment, and smooth operation