1. Using the Item Cloning Glitch:
- Turn off the game and take the cartridge out.
- Rip a piece of scotch tape and place it on the pins, covering pins 1, 8, 11, and 12 (counting from left to right).
- Reinsert the cartridge and turn on the game. Select "Yes" when asked to load without saving.
- Go through the cloning tutorial in-game.
- Now that the cloning machine is built, place the Master Ball in the 5th slot of your bag and put a disposable item (like a Poké Ball) anywhere in your bag.
- Open the cloning machine and click the "Clone" button.
- When you are asked to withdraw a disposable item, withdraw and cancel.
- Now, click "Clone" again and the Master Ball should be cloned.
2. Using a GameShark:
- Turn on your Game Boy Advance with Pokémon Fire Red inserted.
- Turn on your GameShark.
- Enter the code 01003C9D 0064 and press the "Activate" button.
- Go to the cloning machine and click on "Clone".
- Select your cloned Master Ball and click "OK".
- The Master Ball will now be cloned.