It is a very difficult, as to which brand to go with. You have to ask what your aims are for the brand within what you offer.
Ideally I feel you would want a brand which offers very good treatments for your clients coupled with good value for money on a cost per treatment basis. Whether this is a high tech solution to problems or a feel good treatment (it should be noted that skincare can only offer temporary solutions - otherwise it would cross over into medicine).
It is also important that there is something to say about the brand you are using. What is the brand's unique selling point? This can be something as simple as good skincare for different skin types to exotic ingredients. What ever it is, it needs to mean something to you or you will never convince your clients of the benefits.
You should also look at what price the products retail to the customer, are they applicable for your client base. Some of you might be thinking that you don't really want to retail on the products that much, but this is an additional unseen service you offer. You are after all the expert - that is why your client came to you in the first place. And do remember that the effects of the products used in the treatment are only temporary (I am sure we have all seen the disclaimer on products 'used regularly can help reduce the appearance of fine lines and wrinkles'), so it is important for your client to use a skin care product that will continue the benefits of the treatment.
You also need to know what additional services the brand offers. Do you get brochures and are they nice. Is there other support material available? Also does the company charge for these? In this case free is not always better, an ugly brochure can put clients off. Does the brand actively promote you? Does it offer your staff or you incentives? Is the brand strong enough to draw clients in? Will the salon in the next street also have the same brand?
Also do you have to have training to use the products and if you do is there a charge for it and do you have to travel to get the training? This can be a hidden charge by take up your time when you and your staff could be seeing clients.
I guess then, when you have found brands which tick all your requirements, then you have to look into the start up costs and if any deals are available. When you are this far down the line you are likely to know which brand you would like. Don't be scared to ask for a custom package for yourself.
I would also like to say a big thank you to deb379 for recommending us.