layering serums

I think it should follow the thinnest to thickest consistency as well. I'm no expert but summer fridays is supposed to work for mornings as it is a vitC serum and the olay retinol one should be for nighttime. As for all the others I think you can use them day and night. I personally don't recommend using all of them though, maybe try to use on different days?? But that's just me, they seemed pretty hydrating ones..

general rule of thumb is thinnest -> thickest. only exceptions are exfoliants, which should go first, and retinol, which usually comes last