This stand-alone addon allows you to set mount favorites the same way you do battle pet favorites: right-click the mount in the mount journal and Set or Remove Favorite status.
If you use version 2.0.12 or higher of the addon Select, then you can also use /select mount:favorite as a filter to easily choose your favorite mounts in a flyout menu.
The default behavior of right-clicking a mount in the mount journal is to mount/dismount that mount. Since right-click now pops out a menu, you can double-left click to mount/dismount instead.
If you use version 2.0.12 or higher of the addon Select, then you can also use /select mount:favorite as a filter to easily choose your favorite mounts in a flyout menu.
The default behavior of right-clicking a mount in the mount journal is to mount/dismount that mount. Since right-click now pops out a menu, you can double-left click to mount/dismount instead.