EDIT: Side note – one of the clearest (subconscious) dividing lines between "creepy" and "normal" compliments is – how much time am I spending enjoying the thing I'm complimenting? If either your comment implies "I (may) have spent time staring at you to come to this conclusion", or if your focus (eyes/body position) lingers on the person you're complimenting, it will be perceived as creepy. If neither of these is true, it won't.
Examples:
"Nice new frames!" -- noncreepy. Not specific enough to have required more than a second's glance to formulate. Speaker may not even have actually formed an opinion.
"Those pants fit you well." -- creepy. You must have been looking at my butt and thighs for at least several seconds to come to this conclusion. Better: "That's such a cheery yellow blouse!" You could see and judge the color across the office in a second's time.
"I like your haircut", followed by several seconds of silence while you continue to look at me or my haircut -- creepy. You are enjoying this aspect of my body too much. Better: "I like your haircut", followed by topic change or end of conversation.
"You look good today / I like how you look" -- creepy. It's so nonspecific that I don't know what's going through your mind. Better: "I like the new look" (if the "new look" is something obvious), or be otherwise specific.
Note that all the above applies equally across or within genders. I (male) would indeed be creeped out if a male co-worker said one of the "creepy" examples above (with the possible exception of "you look good today", only because I might have more insight into what's in his head, assuming he is heterosexual). And I cannot think of one time a male co-worker has done so.