I recently set out to accomplish an extreme task. Reduce everything I own down to the size of an 18 liter backpack. It was especially challenging considering the "extra" items I needed in order make my living as a photographer and filmmaker. It took three months to craft the perfect bag and towards the end came the not-so-exciting task of minimizing my data storage. In the end I was able to contain 1.2 Terabytes across 12 storage devices, all in wallet a few credit cards thick. There's other ways to do this but I hope I can give you some ideas to craft your own minimalist data storage pack to fit your needs.
Step One, Storage Requirements
What I need for my workflow
As a photographer and videographer, there's two things I want when it comes to data and memory cards and that's speed & capacity (who doesn't?). Even more important in my situation was the weight and volume they would take up in the bag, this means they need to be as small as physically possible.
To accomplish this I would have to switch my memory card system from SD Cards to Micro SD Cards, and switch my hard drive system from Disk Drives to Solid State (SSD).
The Memory Card Holder
This wonderful little piece of plastic is the SDcardholder. It has 10 numbered slots for micro SD cards and one slot for a micro SD to SD card adapter. They also click securely into place with a precise and slightly bendy plastic plank below each slot.
Lexar 64GB 1000x
High end Mirco SD card are plentiful and relatively cheap. In my experience the best value is the 64GB and 128GB Lexar Professional 1000x microSDXC 128GB UHS-II/U3. It works flawlessly with my 4k Yi Action Camera and of course on anything else I stick it in.
PNY SSD
This is the Elite Portable SSD by PNY, this particular model is 480 GB and about the weight of a lighter. It's fast enough for 4k video editing and is among the smallest available.
Higher Capacity Solid State Hard Drive
Slightly more popular is the Samsung T3 SSD, which is available in capacities up to 2TB. The Samsung T3 also comes with a USB 3.0, USB Type C connector for direct connection with the new MacBook and MacBook Pro without the need of an adapter.
Apple USB-C to USB Adapter
There's no way around it, if you have the new if you have the new Macbook or PacBook Pro which only have USB-C ports, you'll need the Apple USB-C to USB Adapter to connect your memory cards to your computer or a hard drive. I have the Macbook with only one port, so for me I have to first import the cards to the computer, unplug them, then plug in the hard drive and transfer them there.
Sandisk Ultra Fit 128 GB USB 3.0
This is just an extra bit of storage because I still had space inside the wallet. It's a 128GB thumb drive that is literally the length of your thumbnail. This is great when you're giving or getting files from someone in person, you can just plug it in to most computers with no sd card adapter hassle.
Chums Surfshort Wallet
After I had my hard drive and memory cards I needed something small and preferably a little padded to store them in. I found the Chums Surfshorts wallet a perfect fit. It's got two zippered pockets, one with a clear plastic viewing screen, a back pouch, and a loupe. It's even got RFID blocking tech, Rip Stop Nylon, a bird driver license which I keep in the pouch window.
Conclusion
In conjunction with additional cloud storage this storage solution could work semi-long term. If you buy the 2 TB SSD and fill your memory card holder with all 128 GB micro sd cards, you would have around 3.5 TB in your memory wallet. As external SSD and Micro SD cards get cheaper, it wont be long before you can have an affordable 4 TB setup in your pocket.