Okay, I'll get toasted by some folks for this, but 'frankly, my dear..."
I have a back inflate BC, too. I'm blessed with a "kangaroo" pocket" on my waist strap, but it's not big enough for everything, and it's a pain to empty the pocket looking for the item on the bottom. Therefore, to keep from cramming all sorts of stuff into it, I added pockets on my tank straps below the buckles. Sure, I know dive shops and catalogues offer all sorts of these, but I "cheaped out". I added two velcro pouches from...ahem... the Warlmart photo dept (they're actually camera cases for digital cameras). One holds my sasage, line, mirror and whistle, and the other contains a backup folding knife. They both work perfectly and hug close to the strap, thus decreasing drag.
Works for me. Now, where's the jelly and butter...let the toasting begin!