it all depends ...
sometimes i sell directly to people i know, or know of, or their friends ..
sometimes i ask a café if they allow local people to put things on their walls ( and i might sell there )
sometimes i might be in a group showing with other people at a larger gallery venue
i have sold off of ebay too, but these days i have a selling page / storefront on imagekind.com, and i have done pretty well.
you have to do all your own advertising, but that is par the course no matter what you do...