Continually look for unique and newsworthy aspects of who you are and what you do. Very often the qualities on which an ad focuses are interesting enough to provide material for a feature article. Word of mouth is the best advertising you can get. Let people know. If what you do is interesting, valuable, and reliable, that in itself is news these days.
Word can get around incredibly quickly.
Position your business where what you want to happen is most likely to happen. The best fishermen go where the fish bite, not where they'd like them to be. That means they know fishly behavior. A conventional bookstore may be the worst place for your manual of tips for sailors. A boat or sports show that attracts 25,000 people interested in what you have to say might be among the best.