Adding or replacing shelves in your cupboards can make a big difference in how convenient storage in your kitchen is. Although it might seem intimidating, this kind of job is one of the best ways to cut your teeth in the world of do-it-yourself. The process is simple and requires only tools most people already have at home. It's also forgiving: the inside of your cabinet is outside the public eye, so your mistakes are out of sight to guests.
Measure the width and depth of your cabinet. Cut a piece of the plywood to match these dimensions.
Cut four pieces off the dowel, each 1/2 inch long. Pruning shears are the best tool for this step.
Set your level along one side of the cabinet wall at the height you want your new shelf. Set it to level, then draw a line along the top with a pencil. Do the same at the identical height on the opposite wall.
Drill two holes at each line 1/4 inch deep using a 1/8-inch-diameter drill bit. Place two holes 1 inch from the front of the cabinet, the other two 1 inch from the back.
Push a section of dowel into each of the holes you drilled.
Repeat Steps 2 through 5 for any other shelves you want to install in this cabinet.
Lay the plywood on top of the sets of wooden dowels. The dowels hold the sheets up in place.
If you want to paint your shelves or apply contact paper, it's much easier to do that before you set the plywood in place.