Flash Hydro-Boost Instant Plumping Emulsion ($42; renskincare.com) is a new launch from REN Skincare, an instant skin plumping emulsion that when activated with water, helps boost hydration levels. Its a thin lotion consistency that needs to be massaged onto skin, then add water and massage more until it is finally absorbed. The key here is to add little water or the product could get a little slimy and could take a while to get absorbed. It is also easier and quicker to work with if you use little water and then add more if needed. It does leave skin looking and feeling more plump and smooth. It is to be used before the start of your skincare routine (before moisturizer) and doesn’t change anything else other than the fact that skin already feels much more hydrated and plump. If you have dry, sensitive or dehydrated skin, this is a great addition to your skincare routine!