There are various ways to use Lumene products. If you want to use their serum, layer it with other serums and moisturizers, and apply it under your makeup. Their pigmented products like the Invisible Illumination Instant Glow Serum are best applied using clean hands or a damp beauty blender.
Lumene gel masks can be left on overnight if you are dealing with serious dehydration or use a daily moisturizer. If not, just leave them on for 10 minutes and rinse with water. You can also apply them before showering, because the steam can help to help the mask's ingredients to penetrate the skin.