It looks like you’re asking this question in good faith, so let me respond accordingly.

Also, since we are the internet, I should say that your mileage may vary. I’m giving you a specific answer that won’t apply to everyone and in all situations. I’m hoping you will generalise this advice and apply it carefully in your particular situation.

Here’s the issue: compliments sound creepy if people get a sense that there is going to be a follow-up that they are not interested in – like you asking them out at a later date. So your objective is to make it clear that you are NOT trying to chat them up now and that you are NOT banking up brownie points for when you do chat them up later.

Here are four tips for being/sounding less creepy when giving a compliment:

(1) Be happy for them. Assuming you really like what you’re complimenting them on, make sure you sound genuinely enthusiastic about it or impressed by it. So, for example, say something like, “I love what you’ve done with your hair! It looks really cool.” in an enthusiastic way. Don’t be excessively enthusiastic because that comes across as fake; be just a little more energetic that you might normally be.

(2) Say more words than fewer. If you were to just say, “Nice top!” they’d be wondering why you’re focusing so much on their top – which then comes across as creepy. But if you say, “I love the design of that top, it’s really well made!” this tells them you’re actually looking at their top and this is not just an excuse for you to look at their chest.

(3) Make it about how YOU feel. Unless you’re a close friend, don’t talk about their appearance in reference to what you’re complimenting them on. So don’t just say, “you look good with that haircut”. When you do that it sounds like you’re complimenting them and the haircut is just the excuse for you getting into their good books. Instead focus on the thing itself and how YOU feel about it. When you say, “I love what you’ve done with your hair!” you’re talking about YOUR feelings. Then if you add, “It looks really cool” you’re talking about the haircut specifically.

(4) When in doubt, don’t give the compliment. It’s better to be quiet than to come across as creepy. And if you give too many compliments, it feels like you’re going out of your way to notice what they are wearing (ie borderline stalking). Also, save your compliments for something that is particularly cool or different. If you compliment something that’s normal (at least to them), it comes across like you’re trying too hard or that you’re watching them too closely. Which, again, is creepy.

If you’re not comfortable with giving compliments, here are two ways you can ease into this:

(1) Do a drive-by compliment. Like if you’re walking by each other in the hallway you notice their top and say, “That green is a such a good colour!” and then you keep on walking. What you’re doing here is making it clear that there are no stakes involved in this discussion. You are not trying to transition this into a conversation or a chat-up. You’re just giving the compliment and moving on.

(2) Compliment in a group. If you compliment people when they’re on their own, it might sound like you’re trying to chat them up. But if you walk into the office where the team is sitting and see someone wearing really nice shoes, you could say in front of everyone, “I love those shoes!”. That will get everyone else to notice the shoes and, most likely, echo your compliment. Then it will become a group compliment and not one that’s coming just from you – even though you’re the one who prompted it.

(3) Practice on your male colleagues/friends first. By giving these types of compliments to men (~85% of whom will assume that you’re not trying to hit on them) you’ll get a bunch of practice and will build up your confidence. And if your female colleagues see your giving compliments to men as well, it’ll be easier for them to receive compliments from you in the future.

Sorry for the long reply, but I hope it helps!

Bottom like: it feels great to receive a genuine compliment and it feels good to give one as well. We should all get confident about giving more compliments to people of all genders.