Unless you have mega-bucks to hire your own publicist or marketing company, you will spend about ten percent of your time writing and 110 percent working hard to have what you wrote, read. Contrary to the opinion of professional PR firms, there are many low cost ways to promote yourself and your book. The easiest, and least expensive is to make your own business cards using your home computer and printer. If you don't live near a store that sells pre-designed business cards, there is an excellent catalogue company called Paper Direct that carries a complete line of business stationery. You might find a theme card that will work well with your promotional material as well as matching brochures, postcards and letterhead.
Colorful cards are attention getters.
I use several different designs for my writing in general and a more specific design for my novel which has a picture of a wine bottle and glass on it. The computer printed cards work well if you're going to a lot of different events. At the recent L.A. Times Book Festival, I substituted my phone number with the booth location number so when I handed out the cards on site, people could find the location of where to purchase my book. At my recent booksigning event, I replaced the booth location, with the Barnes and Noble's store address and phone number. All these changes were free.