I think about it like this. Remember the story about the three little pigs? How one built a house out of straw and it was blowed down. Well that little pig did not build a strong house. In other words you cannot build your platform overnight. It has to be strong. You may be in a hurry to get your great works published but you need to take the time to build a strong base of fans and readers. It take time to develop. Try to find places where you can do some public speaking about what your writing about. Places where you can read excerpts from your books.
The second little pig's house fell down too. He did not build it together tight enough. Make sure to keep your fans interested in you. Keep your blog posts fresh and updated. Offer something for free on your site, make sure you have a site. Some people like newsletters, do a poll on facebook or your website asking questions. Keep things new and tight.
That last little pig, he built his house so strong it lasted. Do your research, check out your competetion. See what they are doing that works, and make it your own. By the time your books are all polished up and ready to be published your name will be out there and you will have a strong platform.