How To Create Custom Menu In ConvertXtoDVD
 

The latest versions of ConvertXtoDVD come with 39 Menu Templates loaded.
"Settings" then "DVD Menus"
Select the template (or create your own) some give video.
Add the files for the movie.
In the Left hand panel "Tree View" click the + on the DVD Options in order to expand the list.
Click the + on Title menu parameters.
Click on Background video/image there is a drop menu "Do not change" select the drop menu to see the choices.

That was for the main disc

If you do the same expanding the + for a title set and then "Titleset Menu Parameters" you can do changes here as well.

You can also change fonts for the text etc.

Sorry I did not have time to break this down into every step.
You could always use the online help from the help tab