I don't know which would be worse - big city or out in the country (in terms of marketing only - I love where I live.)
I use the "E-I-E-I-O" method of marketing.
E - engage others in conversation. Every where you go, talk to people - ask them what they do, and they will invariably ask you what you do - then tell them!
I - investigate opportunities for work. Go to art, craft, and photography shows - look for artists who need work done.
E - enjoin other organizations. There are countless posts and topics concerning Chambers of Commerce and other business organizations. Even the local PTA and other school groups offer lots of promise. (But one word, don't join if you're not willing to work in these groups. Joining just for business contacts never works.)
I - inventory. "Find a need and fill it." Look for what can set you apart from the crowd and make it worth the customer's time and effort to find your place of business.
O - Outlook. Always be on the outlook for ways to market your business in unique ways and areas.
In short - become a guerrilla marketer. Just "advertising" and then setting back and waiting for the customer to appear never works - and works even less than that for the homebased business! Get involved, build relationships, and above all, be visable.
That has worked for me for over 15 years now...