What tactics other than 'setting an example' successfully encourage friends/family/others to become cyclists?
Sex.

Convert them one at a time, starting with the attractive ones. Only date potential cyclists, and slowly convert them while you date them. This tends to produce a solid conversion, because you have the opportunity to reinforce the positives and address the negatives over an extended period.

I've been doing this for a while now but it's a slow process, usually taking more than five years. The benefit is that I have a partner who cycles, but it isn't very good at producing a great mass of cyclists unless you import thousands of Dutch singles. In my case people have asked whether I only date cycling activists. The answer is no, the people I date become cycling activists (well, two out of two in the last 10 years have).