When I build anything from towns to taverns I always start with the people. Once I have created the people who provide the essential services to make the location work and then add their families I have a rough working population. That then tells me how large a place it is. In a tavern you need the landlord or barkeep, a chef/cook, a server or two. In a small out of the way place that could be a husband and wife with their own children or they could be staff and unrelated. What makes taverns though is the client base.