A good idea is to have the Routes, Tracks and Waypoints for a particular ride on a GDB file. After a while, you will have a library of GDB files which are for Calendar events, perms, DIYs and fun rides.
To prepare the Garmin for a ride, clear it and then upload the Routes, Tracks and Waypoints for that ride.
In the Routes list will only be the routes appertaining to the ride. Likewise Tracks and Waypoints.
Any Waypoints, Tracks and Routes that you wish to be on the Garmin for ‘everyday use’, are kept safe on their own GDB file and after the Audax ride, the Audax ride stuff is deleted and your ‘everyday use’ stuff reloaded.