I use the styrofoam case the Phantom comes with inside a 5.11 Rush 72 backpack. I have seen this bag (and others like it) made with custom foam, but they do not IMO have any decent protection over the drone to protect the motors, just a layer of foam. I wanted to be able to shove it in an overhead bin, etc without worry that some tool will muck up something jamming his jacket or cane up over my bag. The styrofoam case survives UPS/USPS so it seems good enough. And it fits in the Rush72 just fine with lots of room to spare.
My Layout:
Have the styrofoam case (containing phantom, remote, cables, props and spares, and factory battery charger.) in the main pocket.
Then outside the styrofoam but still in the main pocket I have a fireproof bag with 7 batteries, a 3 battery+remote charger, and the base station antenna setup for my tracker.
The bottom outer pocket has my tablet, sunshade, spare cables, a 28,000 mAH portable charger, and some stuff like gum, chapstick, headache meds, pad/pen, tissues, lens cleaner, handwipes, etc.
Top felt pocket has my sunglasses.
Front top pocket has my SD card wallet, registration ID printout, spare reg-ID stickers, and several pages of FAA regulations (to show unaware people/officers if need be).
One side pocket has my 40oz HydroFlask (insulated water bottle)
Other side pocket has tools. Multihead screwdriver, Leatherman Surge, Flashlights, etc.
15in macbook and charger fit in the rear pocket if I am taking them.
and there is still room to shove in more stuff.
I have a black one that I use for normal travel, but got tired of packing an unpacking depending on trip, so I have bought another in Double-Tap color as a dedicated drone bag. I really like the Double-Tap color. Well worth the $155 w/ free prime ship from Amazon.
Bug Out Bag RUSH 72 Hour Backpack | Official 5.11 Site
Sorry, can't post a pic at the moment cause the case/drone is with DJI cause the camera/gimble/card reader system just stopped working on my 6 week old P4.