1. Google: The most important thing for a restaurant business is to be on Google, add your restaurant on Google My Business, and encourage customers to write reviews of their experience dining with you. This will definitely increase your reach and credibility.
2. Your Website: A website with a good design & user interface, well-optimized for different devices is very important in your business. Get a custom website that offers your customers different ways to buy to leverage online ordering.
3. Food Ordering Apps: You can list your restaurant on many food ordering websites and apps like Yelp.com, GrubHub.com, Seamless.com, Delivery.com, and Eat24.com.
4. Social Media: People stay more and more on social media platforms these days, so, a good presence on Facebook, Twitter, Instagram, Pinterest, etc. cannot be negligible. Create attractive posts, offer discounts, and engage people.
5. Train your employees: Train your employees to retain customers. If your servers know the names of customers or ask about their families then it will give a good social experience to them. Your customers will keep coming if your employees are trained to give a service with a personal touch.
6. Offering small meals: Give your customers more options with small meals. This will increase the chance of buying from first-time customers as well as returning customers.
There are many other ways to promote a business like distributing Pamphlets and posters, Email marketing, SMS marketing, and Search Engine Optimization. But the first and most important thing in your restaurant is your food. If people love your food, you will increase your popularity and loyalty automatically.