According to the Liz Earle website - use your superskin concentrate under your moisturiser.
Personally, I find it too much to use both. I use either the moisturiser or the concentrate when I'm using LE, but you can mix them together. The concentrate is called a serum, but is essentially made up of oils (including argan oil). Again, my personal feeling, the oil is too heavy for my skin most of the time, and I prefer to use lighter oils such as AD Skin Synergy, which Mr Marple has mentioned, or the Decleor Aromessences., or I use a Clarins blue orchid facial oil. In general with any oil - they seem to sink in better on a slightly damp skin - so straight after toner is a good idea... and apply a very small amount unless you're planning to use it to massage your face - if you're able to create a small pool in your palm you have enough for a massage and too much for general application. As we are all different (and everyone's skin will vary day by day) start with a small amount - see how your skin feels, and if you want to add a little more. Keep it well away from your eyes - it "wicks" into your eye area and can give you lovely swollen eyelids and be generally irritating to your eyes.
