Here’s one- I’ve been doing it for years:
I save all my old issues of model mags (including the Journal!) in a box. Whenever I go anywhere that has a waiting room, I bring a couple along and leave them behind. (FineScale Modeler is a good one for this.) And they don’t need to be current- even two-year old issues are relevant.
I also made up some simple business cards on my computer, printed them out on cardstock. (Ten to a page). They have the name and logo of the club, plus the words “”Model Building Club”, and the URL of our website. I staple one inside the cover of each magazine.