Cut fabric strips on bias (see this tutorial for tips on how to cut bias strips the easiest way; video included)

The fabric strips should be as wide as the larger end of the bias maker and should have a pointy end so you can easily insert and push it through the bias binding maker.

Set your iron on the steam setting.

Push the fabric strip through the large end of the bias maker all the way through the other end (the smaller end)

Slightly pull it out with your hand, just enough for you to be able to see that it's forming into bias tape.

Press with your iron.

Pull the handle on the bias tape with one hand and gently pull away from the iron while pressing the bias tape with the opposite hand.

If you want double fold bias, simply fold again the single fold bias when you finish using your bias maker.