I offer to meet random people for coffee several times a week, sometimes it turns out to e networking, sometimes it turns out to be ad-hoc advice/mentoring, I just try to put myself out there for people to use as they'd like and see what happens.
I created some specific 'coffee' time slots in my calender and use https://calendly.com/ to organise the time slots (and put location details etc in as well) and then I just occasionally post to LinkedIn with the link saying I'm open to chats. I tend to get 1 or 2 every time I post.
It's definitely not 100% effective but works for what I want at the moment.
