Write your own template

Below is the list of templates used by menu.

• template/contenttype/menu.phtml

• template/contenttype/menu/item-block.phtml

• template/contenttype/menu/item-category.phtml

• template/contenttype/menu/item-content.phtml

• template/contenttype/menu/item-custom.phtml

• template/contenttype/menu/item-node.phtml

• template/contenttype/menu/item-page.phtml

• template/contenttype/menu/item-product.phtml

menu.phtml corresponds to the main template used for displaying menu.
menu/item-* are templates for displaying your item, depending of your item type.

If you want to create a dedicated template for your menu, call it:

template/contenttype/menu-identifier.phtml
Where identifier match your menu unique identifier.

The same method can be applied to menu item template, example:

template/contenttype/menu/item-category-identifier.phtml