As described in the manual https://userbase.kde.org/Kdenlive/Manual/Settings_Menu/Download_New_Titl... in the past you could download custom titles submitted by users. However, this feature has been broken since August, 2013.
Therefore the below information is at this point of historical interest only.
If you have created a nice custom title you can make it available to all Kdenlive users.
You can browse the list of existing templates and modify or create a new one. Once a the template is created on the website, it can be automatically installed by all Kdenlive users (requires Kdenlive >= 0.7.8) from the menu "Settings > Download New Title Templates...".