if you have small and oval face , I think the big frame will look cool on you ,but not too big ,otherwise they will cover your face .the Ray Ban glasses are quite good ,you can have a try . Also there are virtual try-on system to help you find the most suitable glasses . you just need to upload your frontal face picture .
oval face are generally considered as the most perfect face. And technically, any glasses frames can will match their looks. And also, if you have a small face, you can try cat eye style eyeglasses that suitable people with small faces. Of course, you shall consider your hair style and clothes etc. Anyway, I think the best way to pick up the suitable glasses frames is trying on.