This is a great link to the Gossmakeupartist blog - a brilliant demonstration on how to use the Rich Liquid Foundation to get the best out of it.
To summarise:
It can be used neat or mixed with moisturiser/ Primer. As Goss mentions, a little goes a long way so mix about one part Foundation to three parts moisturiser for suitable daytime coverage.
Buffing it in with a brush [our Highlighter Brush is my fave for this] will create a flawless look.
The Foundation will last a very long time, due to the consistency and thickness of the formula meaning you only need to use a little of the product.
Enjoy and thanks Goss!