For me, best use of space is 100% the top concern in storage arrangements. This is certainly because of how pressed for space I am at the moment, but also on a more general level because you never know what's going to happen: maybe someone will leave you a bequest of hundreds of items! Maybe you will have to suddenly empty multiple permanent galleries whose objects have no dedicated home in storage!
Looking at your museum's collections page, you seem to have a spread of objects rather like ours in a huge range of sizes (art objects, jewelry, housewares, building parts, etc.). What we do is break down by type of object and then by size. So, for instance, we have art storage with space for hanging 2D pieces and shelves for 3D pieces, and the shelves are at varying heights so that we don't waste too much vertical space. We also have historical artifact storage made up of large shelving units where objects are stored by type: one unit is all lamps and candlesticks, one unit is all hats, one unit is blacksmithing tools, etc. A lot of flat objects like trays and plates are stacked out on the shelves with foam between them, but less obviously stackable items might go in trays inside boxes. For very small objects, we have a repurposed card catalogue, each drawer with a thematic grouping (wax-flower-making tools, coffin plates, writing equipment, buttons, etc.)
In your situation, I would probably break down by size first, but then after that I would think about how curators might prefer to browse in order to choose items for exhibition (either in terms of walking through storage themselves or of asking you to pull items for them - make it easier on yourself). Are they more likely to want to see objects that are made the same way, or are they going to want to see all of the jewelry, all of the bowls, all of the silverware? Maybe consider organizing by size, then object type, then technique within that type?