There are a few different ways, but I always have cut up a sheet of each kind of paper that I have, and keep the strips stored with the full sheets of paper.
When I start printing I start exposing and developing with the test strips, and make sure everything is dialed in before I go to making prints. Saves paper, and that saves money.
Edit, gads sorry I see your talking about film, not printing. Take a scrap of film and place it in your developer,at temp, it should turn black in a minute or two...