This is the first time I purchase anything from MAC. I've recently decided to try them. I went on their site to order, but since I have to pretty much order them individually, I wanted experienced MAC makeup brush users to please tell me the most essential brushes I need for the face, lips, eyes, etc. so that I may order. If you can please tell me the brush number, what it's for, and why you think it's essential, that would be great. Thanks 