This is what your final board will look like.

Step 1: Gather Your Parts and Tools

You'll need a (plank) board, I used simple ply 7mm x 35mm x225 (but 5mm or even 3mm thickness would work).

list of parts

board large enough to handle your paper size
a large clip
a couple of washers (I dug around in my misc. parts pieces box)
three philips head 10mm wood screws (check your screw depth to your piece of wood!)
I used a piece of (ply)wood about 5-10mm thick by 35cm by 25cm (you, of course, can vary the size!)

optional

some wood glue

tools

philips head screw driver

Step 2: Screw in Wood Screws Till Sharp Tip Is Showing

I put the screws through the wood at the top of the large plank/paper sized board until the tip peeked|peaked :) through. I did this so I could then bang the screw tips into the stand off board that I am going to attach.

I put some glue on the standoff board(the glue is optional) then pressed the boards together. The sharp points of the screws kept the boards from slipping around while I screwed the wood screws firmly through the plank board into the stand off board.

Step 3: Screw and Washers to Hold the Big Paper Clip in Place

I used two washers here. One smaller than the head of the screw and one large than the opening of the clip.

I fit the screw through the two washers and centered the paper clip at the top of the plank board. I made sure the screw was also going to bit into the stand off board below and that the washers were firmly holding the clip in place.

This was by far the most tricky part and it took me about 5 seconds to figure out that I wanted just one 'leg' of the clip down.

Step 4: Clipboard Is Finished

And we're done! Really, this project was so simple and CHEAP! I figure it cost less than 1USD TOTAL, including the wood and the clip. Granted, the screws and washers were lying around unused.

I have made three already and my family has asked me to make a couple more for them.