I'd recommend a "power suit" if you have one or can afford one. 🙂 You can get some nice stuff pretty cheap even at Target I think. Or check out department store sales. I think dress slacks and a blazer would be perfectly fine, but it might look slightly sharper if they're the same color. That's just my opinion. Did you have something in particular in mind?
Other than that, just keep things like makeup and jewelry under control (no dangling earrings, etc.), and I think you'll be just fine! 😀