As a man, when I was still dating, I loved when women made it clear they weren't interested or had a boyfriend. They were some of my best friends. We could go out and have a good time and there wouldn't be any sexual tension. We could talk about other people they liked or I liked. I'd wingman for them and they'd do the same for me.
I had one date where we planned on hanging out at her apartment to watch a movie and pretty much as soon as she invited me in she told me that she wasn't interested in dating or doing anything with me. We were laughing and joking the whole night. We had an absolute blast and for years even after she moved and married her husband we'd still talk.