Spark lighters have a shape similar to a safety pin. They create a spark and start gas fires for a stove, torch or bunsen burner. Rubbing a small piece of ferrocerium flint against a rough steel strip inside of a rounded metal hood causes the spark. You can find these lightweight, easy to use spark lighters in most hardware stores.
Hold the lighter in your dominant hand with the active end that contains the flint and steel strip pointing outward and away from you. Hold the flint rod with your thumb and the cupped rod with your other four fingers. Stand in a safe area with no flammable substances nearby.
Apply pressure with your thumb so the flint end touches the steel strip inside of the hood. Hold it in position without scraping it.
Scrape the flint against the inside of the cup. This should produce sparks. Practice this several times to get comfortable with the motion. If it is not working, make sure it is dry. If it still doesn't work, replace the flint.