For the best look, I suggest kitchen scissors. Having a variety of colors of duct tape is recomended. A pen is also needed.
Step 2: The Rounded Edge.
How to solidly cover a rounded edge or corner. As an example, I will be using this cup.
Step 3: The Start
This goes for applying duct tape to any surface. When you apply duct tape, stick the tape to your hand as shown and roll it off your hand. Push the tape as you go along firmly. Crease the tape after, but only on the flat part of the surface.
Step 4: Cutting
On the part that sticks out, cut the tape in sections fanning outwards from the circle. Don't cut any pieces off the tape.
Step 5: Finishing
Crease each tab you cut out individually. The tabs will overlap. You can add a strip of tape going around the cup to cover the tabs if you want to. I didn't need to for the radio.
Step 6: Covering Controllers
Controllers are difficult because of there unique an not-entirely-flat surface. Here's how to cover some.
Step 7: Game Boy: Starting
To get the right amount of tape, pull the tape sticky side up and pull the tape untill you have the right amount. Add a little extra to the end. Then place the tape where you want it using the rolling method. Crease the part of the tape covering the flat areas of the surface.
Step 8: Pens, Cutting And Pasting
Trace the parts on the tape that you want to cut off. Then remove the tape and cut those parts out. Re-aply the tape to the part that you want using the rolling method and crease. You are finished.