Clients need to know that what they are buying, they need and will benefit them. The quickest way to lose clients is to give them the hard sell ! Keep track of what they buy and when,so you can work out roughly when they will need to buy again. Giving the right home care advice is all part of the package, just talk about the products and give samples and then record what they have taken home and ask next treatment what they thought about them.
Also know your products and the key ingredients and how they will benefit the skin.
I always say to my clients that when they have a facial I am repairing and rebalancing their skin and if they want to maintain its condition to use xyz .then their skin will continue to improve, rather than them go back to soap and water and dove, and I have to repair the skin again next month !
Hope this helps !
JoJo x