From time to time we buy the bulk arm and hammer laundry soap that comes in a bucket (probably 3 gallons) we use this for the dog towels, rags etc... when the bucket is empty we rinse them out and use them as feed buckets. They work great- we remove the lid, they have a carrying handle... we can fill it with our feed choice and go to the different fields. One field we carry one bucket filled with dog food, the other with goat food. We have a central feed shed, and out of that we feed 5-6 fields... so we carry alot from field to field.
Having a stack of these is great, I can start filling with the different feeds or mixes of feeds and have them prepped to make it much faster to get through the whole farm.
We also use coffee cans for sharps bins.
Save baling twine too!
Old tarps are great for when we know we will be changing bedding in a stall quickly- and are going to dispose of it instead of composting.
Like at a show- lay tarp down bedding over, wrap it up in one swoop and in the trash it goes.