Here are some ideas that have worked for other clubs.
How about a coffee morning at a local friendly coffee shop as in the photo above? One club has a regular coffee 2hour session on the same day every month. The local paper publishes that they have a coffee session so the club and the coffee shop gets some publicity. A few Rotarians meet for coffee and display a Rotary poster on their table . Spread around a few of those "Rotary Now" mags and other Rotary mags that you never know quite were to put them (usually the bin!). Other people having coffee usually can't help but pick-up them up and scan through. If they want to know more they may well approach you or you can engage with them - but don't push it.......
If nothing else, people have seen the poster and there has been good fellowship.
A display cabinet, glass fronted, locked and visibly displayed in a Tesco Supermarket in Liverpool. Cabinet has the club name and logo and contains Rotary publicity posters. It is also made available to other charities for free display of their material. It is regularly updated by the Rotary Club, who paid for the making of it but NO rental etc. charge is made by Tesco for it being there. A good way of marketing Rotary. It certainly is