When I first started wearing makeup, my face was allergic to some big brand products (I did not think it would happen), that was when I started to pay attention to what I put on my face. I am sure everyone has his/her reasons to go green, but it is always good to know why you would like to "go green". I was horrified because it looked like my face was bruised after I used those products, especially around my eyes, so I started using mineral makeup products.
Once you know your reason for switching, it will be good for you to learn about the ingredients that you put on your skin. The Environmental Working Group's database (EWG) is a good place to start. Currently there are many products labelled "natural" or "organic" but actually they have emulsifiers and added preservatives to prevent bacteria to grow, so always buy certified products from safe sources. You can also do a web search on ingredients that you don't know and see if they are toxic, there is so much information available on the Internet. You can also go to some local organic stores to talk to their staff, I'm sure they will be happy to give you some ideas and/or share some tips with you. At the end of the day, you should decide for yourself what specific ingredients you want to avoid and how clean you want to go.
I'm not 100% "clean" to be honest. I think the 80/20 rule is a good guideline, that is 80% of the products I use are natural and 20% of whatever that's working for me, like hand creams and toothpastes etc. It's always good to test out on a new product before your purchase, and read the ingredient label if you know you have allergies, for example tree nut allergy.
There is no need to throw away everything once you decide to go green. It's always good to switch gradually, and it will take time for your skin to adapt too (based on my experience, especially true for oil products). I first started using mineral makeup products, then gradually started using more organic products such as soap for my face, my shampoos and conditioners, my toothpastes and so on. There is no need to hurry. Once your skin gets used to the organic "food", there is no turning back. Your skin will give a natural glow, and it will thank you!
When I become more aware of what I use on my skin, I always check the ingredients on whatever products my friends and family recommend to me and it often shocks me how many toxic chemicals are used in some products. My friends may sometimes get annoyed and offended when I tell them their recommendations are not good for our skin. At the beginning my family could not understand why I put oil on my face/body. You are not alone in this, if you did not get your friends' or family's support, please know that we are here, and we know we are doing a great thing to ourselves, and even more importantly, to the environment.