Ensuring the Appeal of your Service

Where should you be for your service to be obvious (e.g. shopfront)?  If your location has been decided, how can you ensure that people can find it easily?  How can you ensure that it will be clear to passers by what your service is for?

How can you make your premises appear friendly and unthreatening?  What can you do to help people go through your door?  How can you make sure they feel welcome the moment they enter?