Use 3-second negatives for only one exercise in your biceps workout for 3-4 sets.
Use 3-second descents on one SET of each exercise if you're using multiple exercises for biceps in a session.
The optimal way to use this technique is with a basic exercise like barbell curls at the end of a workout when you have a good pump. You won't be able to go as heavy, but you'll feel the exercise like never before.