Very easy! I put what's left on the backs of ... [SEP] 180 Cosmetics C Booster Vit C Serum w/ hyaluronic acid & Vit E<br />  This products says it helps with hydration, elasticity & suppleness.  It's true! That is exactly what it does!<br />  I use this serum morning & night on clean skin. You just need a thin layer.  I use it on my neck also. Then, just as the directions state- add your moisturizer.  Very easy! I put what's left on the backs of my hands.  I am trying to get into the practice of using the same products on my face &  then on my elbows & backs of hands.  It really makes a difference!<br />  I like the look of the bottle & the thin jelly-like serum.  I've had other Vitamin C serums & I like 180' the best.  It makes my skin look hydrated & feeds my wrinkles some nutrients.  Hard to describe!  Not a 20 year difference but I am 66.  I still look like me-just healthier.<br />  I did receive my serum at a reduced price for an honest opinion.  It's great!  Thank You!!