I prefer a backpack or shoulder bag most of the time, but I've moved my fishing kit into a fanny pack for easier mobility when fishing from shore. It's especially handy when I'm fishing with the kids and tending to multiple lines. Unattended tackle boxes has resulted in hooked fingers more than once. It holds everything I need for a day on the water except a net. I even fit some S&P, fish crisp, bacon fat and aluminum foil in there in case I ever catch my trout.

Mine has two main pockets, water bottle (a.k.a. worm holder) sleeve and a small pocket on the belt to hold my fishing license.