What is a one-sentence summary of the following article?
The best way to ensure that you sound genuine is to compliment someone when the positive thought comes to you. Basically: speak your mind! If you want to say something nice to someone, just do it instead of planning it out. When you're complimenting someone, it's best to focus on complimenting things that are under their control (such as their personality, their accomplishments, etc.). This will help them to feel secure in that positive feedback, rather than creating worry that they might lose the thing that other people find valuable.  For example: "I love how you interact with little kids. You're so patient!" or "You did a great job on that poster! I just can't stop looking at it!" You want to actually compliment them, not some inanimate object. For example,"You look fabulous in that sweater!" is better than, "I like how that sweater looks on you." If you're trying to come up with something to compliment someone on, try to look at the things that you know they value. Look back on your interactions with them and think about things they talked about, or just pay more attention to this in the future. For example, if you notice your girlfriend looking sadly at another girl's clothes and saying that she wished she could dress like that, tell her how much you love how she dresses and that you didn't even notice the other girl. Another indicator you can look at is what someone struggles with. If they're trying to lose weight, praise their hard work and determination (but not the loss of weight itself). If they put a ton of effort into a report, praise them for the quality.

Summary:
Let it come in the moment. Focus on things they control. Focus the compliment on them. Look for things that they value. Look for things that they struggle with.