First of all, you need to find out why business is slow. Is a competing bar getting a lot of your potential customers? Or do the people in your town just not go to the bar?
What I'm trying to say is that there is no such thing as a one-size-fits-all bar. Everybody likes different things when they go to a bar. Make sure the atmosphere/ambience will attract the people in and around your town with the most disposable income.
If you have to focus on selling Budweiser to farmers, do that. If you'll be better off seling Guinness in an Irish pub, so be it.
Look at everything from your potential customers' perspective. Will a young lawyer not go because the gravel in the parking lot may chip the paint on his car. Does the businesswoman stay away because she feels intimidated? Are there people in nearby towns that would love your bar, but don't know it exists?
Some people go to bars for the specials/happy hours. Most regulars go for the atmosphere.
Oh, one more thing. This is more important than anything else so far. Let your hopes and dreams guide you, not your fears.
Live. Love. Laugh. Learn.