I've heard people say give a sample of your work away; but I'm already learning I'm not a fan of that. People seem to suck up the freebies and not give back (a review would do nice; good-bad or ugly). I'm going to say what I'm learning is you always find out what doesn't work first before finding what does work. Check out the interview that Smashwords founder did with Brian Pratt... Great pointers...
http://blog.smashwords.com/2010/12/s...t-to-earn.html