You must have Facebook. Not for any reason other than lots of people use it and it's a route to advertise. There are lots of people that live their lives on social media. There's no guarantee that they will ever visit your venue but they may mention you in posts and conversations with others. Hopefully in a positive way.
The art with Facebook is to use it, converse with customers little and often. You can't afford to spend all day on it and it can become an unwelcome distraction.
Although it's use fluctuates, if you're on it and there is an opportunity to get into a "hashtag" conversation then it can make a big impact. For instance if there is a discussion about cooking fish properly then offer your tips.
Never leave your social media unattended. Get notifications of all comments and mentions. Manage anything negative professionally and politely. Keyboard warriors are very quick to make a mountain out of a speck of dust. Remember that what you say is looked at by everyone. Getting into a slanging match with a customer on Twitter will only put off other people.
Always respond to reviews, positive and negative. Concerned about how to handle a really bad review where everything has gone wrong - don't panic. Do a google search for tips on handling bad reviews.
Who are you trying to target? The lunch time crowd? The after work drinks crowd? Make sure your message targets the people that will actually come to visit you.
These are some of the most annoying actions brands do on social media:
Suggested questions/post topics to get you going:
When posting messages, ensure you hit the right time for YOUR audience. Use any statistics you can from Facebook, Google Analytics etc to see when people are more active. Remember that difference platforms have different people using them, and at different times. You may find visitors to your own website are more likely to be on between 9 and 5, Facebook viewers at lunchtime and evening.
See what your competitors are doing, don't be afraid to "follow" them. You may get some tips and ideas that you can modify or improve on.
Take the best photos you can. That might mean buying a proper camera but it will be worth. A good picture speaks more than a thousand words, a poor picture can work against you. Always check your photos for things you might not really want in them - someone picking their nose, rubbish laying around, a dirty knife in a food shot. Stop and check first.
Don't just stop at photos. Share recipes and general cooking advice. This isn't only useful but shows you do actually cook your food from scratch and it's not boil in the bag or ding-ding meals.