A compliment is a unique gift in that is costs nothing to give but can provide immeasurable value. Additionally, compliments don't just provide a boost in self-esteem for the recipient. They can also provide you with their attention. In the case of a guy who you find intriguing, this can turn their perceptions of you to someone who is also intriguing. Compliments however, aren't just words of appreciation or noticing something you like. Like any gift, choose a compliment with the recipient in mind and be honest and heartfelt. Give a compliment without expectation of anything in return.
Identify what is important to the guy who intrigues you. Although you can resort to general compliments on how he dresses or his sense of humor, compliments that have the most impact typically focus on something about him that is unique. This can include his accomplishments, his passion about a topic or generosity. Speaking with him as well as people who know him can help you figure out the best approach to complimenting him. If you don't know the guy that well, look at cues as to where his passions lie. Photos on his desk of him at the finish line of a marathon can be enough information to opening up a dialogue with him. This dialogue can provide possible facts you can use for compliments.
Think about how you want to give the compliment. Frequently, people cast out compliments much like they cast out a line when fishing, in the hopes that the intended recipient will "bite." Think about the delivery of compliments, particularly those you want to give to a guy who intrigues you, explains the Centre for Clinical Interventions in their online guide "Assert Yourself!" Being assertive means complimenting with confidence, not wavering through words and delivering them in a way that shows you cared enough to put thought behind them.
Use a compliment just once. There is such a thing as too much of a good thing and this applies to compliments. Using a compliment repeatedly can thin the impact and cause the guy who intrigues you to lose interest. Additionally, relying on the same compliment can also cause the guy to wonder if your focus remains on one aspect of him or that he isn't that interesting, except for that one thing you keep complimenting. The impact of a single, well-timed, thought-out and single-use compliment is far larger than using the same line repeatedly.
Time the compliment so that other factors don't dilute it. Timing is everything and you should time your compliments for maximum impact. Don't focus all your energy on giving the compliment, but be aware of ambient noise, such as people talking to the guy who intrigues you or escalated emotions that can devalue the compliment. The ideal timing is a quiet location at a time when emotions are calm but upbeat. This isn't a proposal, but it's important to give the guy the compliment in a time or place where they have time to digest and respond.