Make sure that you have all requirements.
Remove ink from pen.
Cut the cotton bud in half.
Insert cotton bud into pen and secure with tape.
Wrap aluminium foil around pen (make sure it also touches the cotton bud) and secure with tape.
Add a droplet of water on your finger and damp the cotton bud to make it work.
Now you have your stylus, enjoy surfing the web or drawing on your device! WARNING: Results may vary of working or not. It depends on which pen you use.