There are very few guidelines as to how you can get your message out there.
There are many creative ways, some subtle and some not so subtle, to do it. Here are a few examples :

A double effective sign. Not only is this citizen's group getting their name out there but by their civic commitment they are getting it out in a responsible way.

Whatever your skills there is always a way to get your point across.

This local quilter decided to put some bones (albeit mushy) in her work to let her neighbors and community know how she felt.

"For the birds"
A local woodworking hobbyist also makes his views known, not just to the community but to winged creatures as well.

OUCH!

Friends of Hudson 'put a hurtin' on the plans of St.Lawrence Cement with simple and effective tools like this flyswatter.

Generally reserved for wealthy politicians and a $3 drink specials at a Tiki Bar, this could be a way to reach a big crowd of people with impact that might be more cost effective than trying to "paper" the crowd.