No matter how you organize them, make a back-up on an external hard drive and make another back-up on another external hard drive. Keep one of the back up drives at a friends house, or a bank safety deposit bank, someplace safe. I had an external hard drive crash just like computers do and I needed my spare back-up. Also a few years back a well know embroidery designer had a house fire and lost everything. She had a spare external drive stored off site.