Pretty much every day, multiple times a day, with strangers, acquaintances, and friends. I think it usually brightens people's day, and with strangers, I think delivery and content is much more important than what I look like or who I am.

For content, I only compliment choices, not attributes:

"Cool shirt!" is good, "Nice legs!" is not

"I love your haircut!" is good, "Your hair has such a nice texture!" is not

Tailored compliments are even better, ex. "That book (or other media) is awesome!" is great, if I really do like it, and it can start a conversation, but obviously I don't lie and pretend I know it when I don't.

For delivery, I keep it light and casual. I am mindful to only do it when they aren't preoccupied, like on the phone or reading something. For tone, I guess I pop the compliment, smile, and movie on. For example, if we're walking past each other-- I don't slow down, and I look away immediately after giving a friendly smile. I don't mean that I don't care about their response, because of course I'm mindful to be sure I didn't offend them, but I don't burden them with needing to respond with gratitude or happiness. I think of it as, I want this person to have the (hopefully pleasant) information that their choice was seen and respected by a stranger. I don't want anything back from them.

I would say 95-100% of the people I compliment seem to be genuinely happy I did, and of the ones who don't react positively, I'd say the vast majority react neutrally. In the rare case where my compliment has totally failed, I usually go "Oh! I'm sorry" and again, disengage.

Obviously, with friends and acquaintances the options open up a little more, and usually I do follow up/continue the conversation instead of moving on. But it's similar in the philosophy that I'm usually just trying to give them positive information, and not seeking anything in return. Compliments are not a tool to get people to talk to me or be friends with me. That can and does happen, but it's not the point. Honestly, I think that's the part that most people struggle with, if they feel like they don't get good responses with compliments. It's not for us.

I do think I'm probably an outlier, because I give compliments a lot. But I continue to do it because it seems to really make people smile!