How should I go about bathroom lighting fixtures near the mirrors?

I am remodeling my bathroom. I am planning to get the bathroom lighting fixture just near to the mirror. But I am perplexed about where near to the mirror should I get this bathroom lighting fixture. Should I mount lighting fixture on the mirror within the framing or above the mirror outside of the framing. It is least expensive when done above the mirror but I was told by one of my friends that It would not look good. So I want to know from you people about how to go about bathroom lighting fixtures near the mirrors. Can someone help? Thanks.