I agree with Janelle too- it's supposed to make you look like you have a tan. You can't go too dark, or like Gail said, you'll look like an oompa loompa.
Since it's sunny here in Hawaii all year long, I can use bronzer all the time and look natural. Bronzer is not really recommended if you can't tan all year long where you are (and I don't mean in a tanning salon!).
NARS Laguna is a very popular bronzer. If you're darker, like a MAC NC35 and up, you may want to try NARS Casino since it's darker than Laguna.