More cyclists need to die.
Unfortunately I'm not joking -- a lot of the protected bike lanes we've gotten recently have been along stretches where cyclists (sometimesore than one) have died. That's what it takes to override the nimbyists in the local Community Boards.
But for a less morbid suggestion, you should join Transportation Alternatives (and its mailing lists!) and go to the Community Board meetings they send notices about where bike lanes will be debated. Every voice in favor helps. I've spoken at a bunch of em.