The order in which you apply your products does make a difference. Following your cleanse & tone, your serums should follow. These include your skin nutrition serums, such as antioxidants & peptides, and will typically have a greater concentration of actives. If you have two serums to choose from, apply the one thinner in consistency first. Anything water soluble should go first. Next up, your moisturizer, followed by, what else? SPF each and every morning.