I have a co-worker who often comments on my appearance. Her comments aren't negative, but they are unwelcome. How do I politely get her to stop?

There are two steps you can take. The first is direct confrontation. Calmly approach your co-worker and say something like, "I notice you keep commenting on my appearance. What's up with that?" She'll probably deny it, at which point you should remain composed and say, "Your comments make me uncomfortable." Next, request she stop discussing your appearance in public. While this tactic probably won't elicit a constructive response, you will put her on notice that you're going to call out her behavior. Doing so makes it likely she will stop the unwanted fashion commentary immediately.

But if she doesn't cease and desist, you need to take the next step and discuss the problem with management or your human-resources department. Explain the situation, adding that asking your co-worker to stop hasn't worked. Then, request that managers take whatever action they feel is appropriate. By taking the problem to management or human resources, you may put a chill on an already tense relationship, but at least you won't have to feel like you're on the red carpet while at work.