I do not hang on to everything from my kids, I hand on to the ones I absolutely love. The stripey suit from infancy, the little moccasins I made. These boots have seen better days, so I felt they would be perfect as planters.
To turn old boots into planters you just need to be aware of drainage. put enough pea gravel or small rocks in the base to give the water time to evaporate that makes it there. I suppose you could drill holes through the base of rubber boots, but that’s harder with other shoes, which you can also use. cowboy boots are very popular.