If your microwave is on your worktop or kitchen platform, you can store a toaster or a juice maker on top of it. If possible you can use them as it is, which saves space and also keeps all appliances together at one place for easy use.
Storing plastic boxes, a clock, or a flower vase, or any small thing on the fridge is not uncommon. You can also store jam bottles, sauce bottles, bread spreads, and other items that you usually eat at breakfast or for evening snacks.
Hooks take up very little space especially if the items are small and long. You can hang knives, different ladles, graters, pans, cups, chopping boards, etc. You can even hang a basket and store fruits in it!
Sure, the utility cart will occupy some space, but you get a few more racks to store your kitchen items and utensils. Plus, it has wheels. So you can move it in or out of your way as per your convenience. Storing the utility cart itself somewhere wouldn’t be a problem...