I was talking to one of my best friends who also happens to be a coworker the other day, and I said "Hey, if you're ever a victim of sexual harassment, what can I do to make you feel comfortable with coming to me so that I can attempt to help?" She said "Nothing, really. The problem is that most harassment isn't blatant, it is hidden and not obvious. It's like a feeling that you get from someone. I can't tell you how…
Networking is the most straightforward answer there. Every time you make a new hire let her know first. Let her know that you understand that feeling isolated in the workplace can happen for a lot of reasons, but if you are of a legally protected status there are steps as her manager you can take to alleviate that. Give preference to candidates she recommends and feels comfortable with.
I would further posit that the norms of tech culture that isolate some and include others and this culture as it intersects with hiring is basically just a way to normalize, refine, and study turnover in tech business by managers and CEOs.
I remember when I had my, "a-ha!" moment working at a coffee shop in highschool. "why?" I thought, "would my employer show a blatant disregard for sexual harassment, sexist hiring policies, hazing, poor scheduling, and offer few benefits that attract long term employment?"
Because turnover is good for business. Lower salaries make coffee shop margins possible and fresh faces bring more customers.