Directory Submission can make your site listed in major search engines. By directory links your site can be in good ranking also in search engines. Dmoz is one of the best directory. If you list your site in dmoz your site can be in honorable status.
There are some tips of directory submission.
Make your site Title Unique which will display as anchor text.
Your site description should be also unique and it should be in 150 character because most of directory accept 150 character description length.
Write keywords for your site page properly which is targeted for that page.
Use paid email id. Paid email id will make guarantee of approval however free id is accepted by almost all directories
Choose that directories which has some PR and which is fast in approval.
Use Robo Form it will make your task easy and you can submit many directories in less time.
Use always home page of your site for directory submission because most of the directories don't accept sub pages of site. But many directories accept. So, separate that list.
If directory shows error as “Title is not unique in the parent category”, change your link page title. Create alternative title for your page also if you get this error.
Maintain all submission properly in excel sheet. In this format :
Always submit your link in relevant categories.