Anything can be a container
Long before being quarantined in the garden, I always re-purposed a wide variety of things, turning them into planting containers.
I've gone through a few watering cans, boots, garden carts and many more things.
Most have a special meaning, that's one reason they are recycled. The garden cart was a gift from a good friend who sold my wife and I our first house in 1983. The boots came from my wife in the 1980's. They were expensive and bought as a gift when we didn't have much money. One of the watering cans was a gift from a good gardening friend. Being nostalgic is a blessing and a curse, but I couldn't bear to throw them out.
The most important aspect of any container is drainage. Drill or poke holes in the bottom so excess water can drain. Next is choosing the right plant for the right sized container. Sedum is fine for a pair of boots, but a tomato is going to need a 15 gallon pot.
Stuck at home, try to find a medium to fill the container. I've got left over pots that I'm dumping for soil, digging in my compost pile and even excavating under old piles of leaves for good stuff to plant in until it's permitted to go to a nursery or garden center again.
If you don't have a garden and want to grow your own food, containers are a great idea. Even some lettuce seeds sowed in a small watering can will produce some fresh greens. Bigger is usually better for containers as they don't need to be watered as much. On the other hand, larger pots are hard to move once filled with soil. Lettuce, beets, other greens, radishes, Swiss chard, spinach and many other plants will thrive outdoors in the cool spring. Later on warm season crops like tomatoes, beans and peppers can be put in place.
I like to fertilize mine every other week now and then every time I water during the summer. I use a liquid organic fertilizer called Grow from Espoma.
Look around the house, garage and garden for a cool container project to keep you busy during these strange times.