Here is how I pack the new backpack for DMing D&D 5E.
Starting at the top of the pack, there is a small compartment, meant for earbuds, chargers, etc. I don’t really use it much.
Next is the large upper compartment of the pack.
I keep the dice case in the dice tray, held in place with provided elastic straps.
On the right in an internal pocket, I keep my “Healer’s Kit”
I kept getting annoyed trying to find how much healing each healing potion did, and finding sufficient d4s for it, so I made this kit. On the inside of the lid it has the values for each healing potion category, and an important reminder: It takes an action to quaff a potion!
On top of the healer’s kit, and in the upper left mesh pouch, I keep some sets of spell cards. In the upper right mesh pouch I keep a set of extra d6s, because it is the one die that uses multiples the most often. Fireballs, anyone? Green for green flame.
Moving out of the upper compartment in the side compartments I keep more sets of spell cards (for different types of characters. In the bottom right compartment I keep a bottle of water for cleaning wet erase markers off of game mats. I also strap my game mat to the side of the pack inside a dry bag.
In the pocket on the outside of the main compartment “door”, I keep my folders and character folios.
In the mesh pockets on the inside of the main compartment “door”, I keep the spellbook for my wizard (I made it before I really started collecting spell cards), wet erase markers, other writing utensils, a laser pointer, and some paper towels for cleaning the game mat.
Now, for the main event, I have the main compartment fully expanded.
I keep a lot of rulebooks with me, the core 3 + Xanathar’s Guide + whatever hardcover I’m running are the main ones I keep with me. I use the Dungeon Master’s Screen (Reincarnated version), with a few notes that I’ve attached to it.
I also keep the toolbox and flatminis case in there for minis and tokens.
I also have a small card folio that I use whenever I need to compile a spellbook for a character from my spell cards.
And, there you have it. My massive DMing bag of holding set up for Adventurers League nights. There is more I will probably throw in here if I run homebrew games, but this is going to be it’s usual configuration.