First, when you teach a class on some aspect of writing, people view you as someone who has something good to say. They also get to know you and you no longer become "just a name" on the cover of a book. When you teach, you become more credible to those who attend your workshop. Look for ways to teach and share with others. Go to your local Junior College and offer to be part of their continuing education program.
Second, Accept any and all opportunities to speak at special events. Again, you move from stranger to someone that people connect with in some way. Make it enjoyable. Share humorous stories. Be careful and DO NOT make it a sell, sell sell session. You want people to listen to your heart. You want them to feel inspired by you. Then, they feel like they know you as a friend and friends buy friend's books.
Lastly, join a writer's group, or start one in your town. Networking goes a long way. You and your group all push and lift up each other. Everyone shares and gives and spreads the word. When you have news, they all post it on their sites and they talk about it. When someone in the group has it, you do, too. Get together and have your own group book signing.