I don't think the alternative to being secretive is offering unsolicited advice. There is nothing wrong with helping people, but instead of trying to approach people about their finances, which I don't think is appropriate unless they've asked, you could hold yourself out, in a public or general manner, as someone who can provide this type of service at no cost. Either on your own or as part of another service organization. Apart from that, I think it's very Mustachian to volunteer your time and, for instance, as a mentor to young adults, you'd have a good opportunity to impart financial wisdom.