I'm not currently looking for any new partners, but when I was I had an OKC profile where I mentioned my relationship structure in the first paragraph and linked to my wife's profile. Whenever I messaged anyone I again outlined where I was at regarding relationships. I wanted to weed people out as quickly as possible so I could focus on better matches. It worked.
Some people that I'd messaged hadn't mentioned being poly until I did. In messaging anyone, I first went through their profile and their questions to see if they were someone I'd want to know better, and then sent them a message that made it clear I'd actually read their profile. In the space of a few months I had dates with several poly friendly people and ended up seeing one for a bit over a year, with us being mostly friends now that she's traveling the world indefinitely.
If I had more time I might have dated more, but school and work keep me busy for now. A fair number of people initiated contact based on my photos of me actually doing things I enjoyed vs profile shots of simply standing in front of a camera.