Stop your concealer from creasing by changing your routine. Make sure you're using a relatively thin formula under your eyes, not the thick stuff you'd normally use for covering blemishes. Beauty vlogger Bella Fiori shows us a great technique in her video on this topic. Apply only to the inner corner under your eye, before sweeping down across your cheekbone. Use a damp sponge or brush to blend up under your eyes and into your cheeks, then let dry. After it's dried, gently pull down on the skin under your eye, and carefully blend out any creases that have formed using your fingers. Once this is done, use a translucent setting powder and a soft brush to gently add a light coating of powder over your under-eye area.
If you're especially prone to creasing, you can try "baking" your makeup for longer crease-free power: After applying a much thicker coating of translucent powder, let it sit several minutes, which will "bake," or set, your base makeup. Then use your fluffy brush to dust off all the excess powder.