Just ignore for now frugal, as it might confuse yourself.
Frugal idea meant for the hdd , it similar to the stuff on usb but not identical.
Make in those simple three steps as explained above and a bit more by BitJam.
Re do a full featured LUM Live USB. Ignore the free space.
The ext4 partition you can use for other stuff as well.
when you Live-booted you'll find a Live Storage folder, within the home directory
which is linked to a folder on the ext4. so you can save and copy data from the running Live
on the the ext4 partition. You can also create any other folder on the ext4 to use for data etc.