Put a little bit of blue tack or double sided tape on your thumb

Push a toothpick into it like this

You are ready for the trick

When you open your hand the toothpick appears to have vanished

But really it's just on the back of your hand

To make it reappear just quickly close your hand

You can take the toothpick out of your hands after the trick and tell the audience to examine it while they are examining you can quickly take the blue tack off so you can show them your hands as well

Have fun and Enjoy :)