Take the concealer you currently have and put a bit in the palm of your hand. Take your finger in a circular motion and warm up the concealer a bit before you apply. If that doesn't work, take a bit of your oil free moisturizer and add it to the concealer and repeat the palm process. To help conceal really bad undereye circles, a concealer with a yellow undertone works best. You can use a yellow concealer under your flesh toned concealer for better coverage. One that works pretty good is the Physician's Formula Gentle Coverage concealer in yellow. It looks like a lipstick tube.