On a long pitch, a leader may not want to take the entire rack of gear with them. Or, your route may require some extra large cams higher up, but not on the lower pitches. So, the question: what do you do with the extra hardware? The place you probably don’t want it is buried down in a haul bag, making it hard to access. (It’s good practice to minimize the amount of time you spend burrowing through your main haul bags during the day.)
Instead, try this. Get a Fish Beef bag, size large, or similar heavy duty stuff sack. Girth hitch an old-school sewn loop daisy chain into the sturdy loop of the bag.
Clip your extra gear to the daisy loops. Never put loose, unclipped gear into the bag, because the chances of dropping it are huge. The leader can add and subtract gear from this “gear closet” bag before they start the pitch, or they can use a tagline, trailing a small diameter tagline and hauling up gear as it’s needed. (Tagging is a great approach on a long pitch, because you start with a much lighter and easier to manage rack.)
You can keep the gear closet on a gear tether hanging from the main haulbag, if you really trust the tie in points, but most folks will probably want it inside the top of the main haulbag.