This is really hard to tell. Just go an famous store that near to you and choose a good quality plastic glasses frames. If you want to buy them online, you cam search glasses in Google and there will a list of glasses shop. And the most top glasses shop usually a good place to go. Personally, i prefer to go Firmoo where i can get good plastic glasses frames at cheap prices.
Personally i prefer to pick out cheap but good quality plastic frames online and it has never made me disappointed. Choosing a reliable store is quite important. If you search "cheap glasses online", you will get many results like zennical, eyebuydirect ,optical4less, Firmoo and so on. According to the reviews from their customers and fans, they are all good stores. You can have a try.
There are many places you can get the plastic frames for women. Firstly, you can go to some entity stores. They have many brands and good service for you. You can also consult the technicians there if you have some related questions about the frames. Secondly, you can buy your plastic frames online. There are many online websites and stores selling plastic frames now and their goods are sometimes cheaper than other entity stores. You can definitely find your plastic frames online, for they have so many choices for you. You can have a try.