To be listed in a directory, a real person will have to look and judge your site. Every site listed must meet certain criteria, which varies with each directory. No directory will list a site with broken links or graphics, regardless of the quality of it's content. Incomplete or Under Construction pages will not be listed. If your site is finished, make sure all Under Construction signs are out of site.
Content is the key with the directories.
Most directories do not consider themselves 'judges' but instead providers of useful resources. The better your content, the better chance you have of being listed. Test your site on 28.8 and 56k modems. Make sure your front page loads within 10-15 seconds. Make sure the navigational interface is clear and concise, without a lot of distracting elements.