A church open house with free refreshments, ideally on a day when there is something else going on in the area to draw people there (like a street fair) is always a good way.
My hometown had a “Church Walking Tour” a couple years ago where about six different churches, including one Roman Catholic, a couple of Eastern Orthodox, and a couple of Protestant churches all opened their doors on a Saturday between certain hours and we all walked around to the churches and got literature and heard a little talk by a clergy person or designated welcoming speaker, at each one.
It was a nice way to see the inside of churches I would otherwise never go into, and learn a little about different religions. It was also well attended and several of the churches had snacks.