Make sure your hands are clean and free of debris before taking a fingerprint. Also, have a blank piece of white paper available to use for printing.
Take an impression of all of your fingertips. You will find that some fingerprint patterns are much more detailed than others making for a nicer looking finished piece. Press your finger in the ink and then LIGHTLY tap on a blank piece of paper. Attempting to 'roll' your finger will only distort the print, so just tap gently like you would to test a hot surface. If you have questions about your prints clarity, ask your local retailer for assistance.
Note: This same process can be applied to capturing hand and footprints.