[rsync] include-from with different source points

[GravyFace]

Trying to automate backup of the following local mounts/directories to
a usb drive (/mnt/usbbackup); here's what's in my include file:

+ /home/gravyface/www/*
+ /mnt/datadisk1/music/*
+ /mnt/datadisk2/projects/*

If I run the following, nothing happens, so I checked the man and I'm
not specifying a source (I thought the include-from was the source):
sudo rsync --progress -avz --include-from=/home/gravyface/backup.list
/mnt/usbbackup/localbackup/

I then tried the following, thinking "/" would be a common denominator
in the paths in my include list:
sudo rsync --progress -avz --include-from=/home/gravyface/backup.list
/ /mnt/usbbackup/localbackup/

...which then starts backing up the root partition, which is not what
I want (but what I asked for, presumably).

Searching the web for examples of local backups returns a lot of shell
scripts looping through directories, calling rsync for each iteration.
 Is this the route I should be taking? " --include-from" seems a lot
cleaner to me.  Perhaps simlinks are the answer?

TIA,
gravyface