These are the supplies that you're going to use. Easy to get, right?

Use the real pick (also known as plectrum) as a template, and draw its outline on the plastic card.

We can obtain up to 5 picks from a regular card.

Cut off every pick. Be careful!

Compare your unfinished plectrum against the real one, in order to use this one as a guide to trim the leftover...

... this way. You might tape them together.

$Polish the edge with the nail file, at a 90\u00ba angle. Thus, you will soften the most irregular edges.$

Polish the edge with the nail file, at a 90º angle. Thus, you will soften the most irregular edges.

$Round the edge with the nail file at a 45\u00ba angle.$

Round the edge with the nail file at a 45º angle.

Lastly, polish the edge by rubbing it on a paper sheet. You may also rub it on a cloth, like your jeans, so you get a smoother finish.

Here they are. Your own guitar picks. Even though you don't play guitar, you can give them to your musician friends.

How to make your own guitar picks

Make the most of those expired and useless credit cards, and make a good use of them.