Work from the inside out. Remember, the people you work with are your customers (inside) as well and how you treat them directly reflects how they treat your external (outside) customers.
Step2
Give your customers what they want. If you have something advertised, make sure you have that item or at least a substitute. It alleviates the disappointment of visiting your location for something and it not being there.
Step3
Remember that your paycheck comes from your customer and if they don't like your service, they can go somewhere else, a place where they (and their money, are appreciated. You have to let them know why your place is the best place for them. Think about how many times have you driven across town for something just because the service was great (even if there was a closer location). Food for thought. Hope this helps.
Tips & Warnings
Customers have lots of choices and they chose you for a reason. It's easier to keep them with great service than it is to lose them and then try to win them again.
Lost customers are harder to win because they no longer trust you. Winning trust is alot harder than working to keep it.
Enthusiast 
