I have created the {{ColorSchemeEntry}} wiki template which can used to quick and easily add a new theme to the sample list table on the wiki page. Simply edit the section and add the code on a new line between two other entries.
Make sure to add a link to your User page you want the theme to be on (but don't actually create that page yet.) Save the change, and in the table there will be a link to create the new user page for your theme, with all the code and formatting already in place.

For more details click the link above.