I use an old style Plano waist pack (they don't make it anymore.)  It has two zip pockets that hold 3 @3500 Plano boxes (which are smallish) and has one other zip pocket that can hold soft plastics, stringers and snap weights.  I'm also able to get my Lipper and pliers in there as well.  So it's pretty compact and forces me to make choices before heading out.  I modified the pack by adding a better buckle but over all it's held up well.  I do carry some other stuff in a binder  - extra soft baits, line and the like but I pack that away since its back-up.  I've only been fishing for the past 6 years or so, so each season I'm getting a little clearer about how much I really need to take.  I tend to use the same stuff over and over and all that other stuff that I couldn't leave behind just ends up sitting there, laughing at me each time it gets carried back and forth across the portages.