Hi tennbee.. Just use it when you feel any hairs or fuzz on your face.. There is no set time for it.. and it doesn't irritate the skin for me.. If you have more of the stronger black hairs, you might want a wider plucking area on your epilator.. which usually indicates slightly more expensive model, I guess.. My black hairs are random, and the little one works for me.. As I said before, it doesn't hurt.. just feels like using tweezers.. but is way more efficient. Let us know what you try and how well it works for you please...