Very easy 20 min weekend project.
Masking tape/ Painting tape (I used the latter)
Step 1: Draw a shape that you desire that is easy to make (one with corners not rounded would be easiest)
Step 2: Trace the shape onto the cardboard and cut
Step 3: Cut out and tape
Step 4: Add extensions to hold small objects that's needed near the desk
Step 5 (optional): Wrap with colored paper to make the tape job bearable