There are many references in the book to a website done by the Environmental Working Group called the Skin Deep Database, which allows you to look up almost any beauty product and see it's safety rating, which is really helpful The advice that the book and the website give as an underlying philosophy is "fewer products, smaller amounts, less often" which is something I can work on, I think.
I've already made a bunch of changes, and I'll continue to work on being more aware of what my skin is soaking up. In some cases, choices I've made over the last few years were reaffirmed, such as natural toothpaste and hair products. There are some things that I will continue to use sparingly, infrequently, feeling guilty every time: lipstick and nail-polish. A few of the changes were no-brainers: toxic synthetic perfume out, lovely natural perfume in. A few are works in progress: I'm cautiously optimistic after a few funk-free days with the natural deodorant, but the old stuff is still on stand-by. One was not at easy as it seemed: I'm perhaps the only person allergic to the most natural soap ever, and have an itchy full-body rash to show for it. As a result I'm going soap-free until it clears up, then I'll try something else. There are a bunch of products, mostly makeup, that I'm going use up before I replace, but I'm going to be more conscious of when I really need to wear them.
So when do I need to wear make-up? I never look like I'm wearing much, but I wear a range of products most days. I can forgo lots of things on the weekends, but at work I like to look pretty put-together. The big thing for me is mascara, because my lashes are so invisible, I feel like I look weird without it, but I'm trying to tell myself so what if I look weird? Going to the gym, for example: some girls look great at the gym, full hair and makeup, smelling great... but I went without a stitch of makeup yesterday and felt fine. There are two pressures at work, I think. One is my own vanity. I want to look nice, in case I catch a glimpse of myself in the mirror. I'd rather not think, Eh, should have worn mascara, but I think that's something I can get over. The second thing is this feeling that I owe looking pretty to people. It's that What Not To Wear ethos: how dare you go out in public like that? But who cares? In some situations, like the gym, or grocery shopping, or a weekend outing, I'd rather assume that no one is freaking out if I'm not fully painted. Anyway, I know I'm rambling, but I guess it's an evolution, finding what products work for me, and what I'm comfortable with.