Perhaps it would be helpful for those of us fortunate enough to have found compatible mates to describe how and where we met them.
In my case, I met my wife in college. Fran was a biology major while I was in engineering. She is atheletic and intellectually gifted. Her father was an electrical engineer and he imparted to all his kids an appreciation for science and the importance of an analytical approach to problems.
Fran is especially attracted to the Extropian ideas of self-transformation and boundless expansion, all part of a general attitude of self improvement. She comes from a secular Jewish background and did not have much belief in conventional religion to overcome, and so the Extropian idea of eventually overcoming death through technology was appealing.
Not everyone will be fortunate enough to find someone like my wife, but I would think that looking among women in the sciences would be a good place to start. Of course women are underrepresented there but in some fields they are a substantial fraction. These people are already accustomed to thinking analytically, they will tend to be less religious than on the average, they are aware of the importance of technological progress. They are also accustomed to being around men who have similar attitudes so they must not hate them too much or they would have gone into another field.
Fran also likes to swim, bike and work out at the gym, but I don't think you'd find as large a fraction of proto-Extropians there. Gym people are interested in self-improvement but they mostly don't have the technical background to appreciate the more advanced ideas of Extropianism. Still, if you looked for a scientifically or technically oriented person who also enjoyed sports and working out, and you cultivated similar traits yourself, I'll bet that your odds would be significantly improved.