Re: How do you keep concealer from creasing and settling into fine lines?I don't know how old you are but many times part of the problem is lack of hydration to the skin. Your skin is the last to get vitamins so if you have a stressful life, it will show in your skin. Start with drinking more water and take vitamin B12 and D to help your body to take it in better. Then make sure you use a good day cream and night cream, as well as a good eye moisturizer. You makeup will look better.
Now for application....
On older skin I like to use liquid concealers because it lays flatter against the skin. My favorite is Effecerns by Lancome because it is waterproof so it sets very well without powder. When you are putting it, use a brush. Use a little bit at a time, and then pat with your finger to blend it. The warmth from your finger will help you blend. If you need more coverage don't get more concealer from the tube, just use what is remaining on the concealer brush. That will keep you from using more than you need.
For those who love cream concealers instead, you don't have to switch. Many times the driness in the skin absorbs the moisture out of the concealer causing it to crack before it can totally set. So if yours does that try using a little eye GEL or vitamin E on top of your concealer. It will give you the moisture that you need, and help it to blend smother. Pat on the gel or vit. E with your finger and follow it with a clean makeup sponge. Wait for a moment to see if you need to do any more patting. If your concealer looks good, then use RICE powder on top to set it. Rice powder is very very thin, so you don't have powder build up under the eye. Brush the powder under the eye, and then PRESS the powder into the skin with a velour puff, or a sponge wedge. This will make it SET, and keep it from sitting on top of your concealer thus undoing all of your hard work.