So glad I found this thread. I'm bank fish about 95% of the time and I've been adding and taking out things from my bag. I use an Outdoor Products Traverse backpack. It was like $10 from Walmart and has plenty of room while keeping me from taking every piece of equipment I own.
Rods: BC with 12#
Spinning with 8#
Backpack:
It has 3 pockets with the largest having a sleeve against the back to hold a hydration system which holds my soft plastics. The pocket itself holds 3 3700s but I only have 2 which leaves room for a light jacket or something else.
A smaller pocket which has small pockets on the inside which holds scissors, wacky tool, knife, pliers, etc.The pocket itself is perfect for a scale, first aid kit, extra spool and line, sunscreen, extra face shield, etc.
And a small pocket in the front which could hold any other sort of accessory you need or phone, wallet, keys, snacks and stuff like that. Also has a water bottle holder on either side which I usually put 2 half frozen, half water bottles which will thaw throughout the day.
nothing special but I feel it works better for my use than having a backpack that I can just weigh down with 30 pounds of gear.
Word from experience: bring a change of clothes just in case it rains or you just end up getting wet during the day. Never under-estimate the value of a dry pair of socks for an hour drive home.