It sounds basic, but a quick walkaround can reveal quite a lot. Look for anything out of the ordinary: bulges, deep cuts, uneven wear, embedded objects like nails or glass. If your tyre looks distorted in any way, don't ignore it - it could be hiding internal damage.
More than six years with a large, sometimes painful plantar wart on the bottom of my foot. The doctor tried freezing. I tried apple cider vinegar, aspirin, freezing at home, over and over again...nothing worked. Never showing the bottom of my feet, refusing to get a pedicure with the girls, and so, so embarrassed. It felt as if I was doomed to have it forever; it was resistant to everything. Literally six years of fighting it, and on a whim, I tried these because of the good reviews. ONE APPLICATION. I wore the bandage overnight. I didn't think it did anything, but a few days later, the wart just came off. I know it's silly to be so emotional over a stupid wart, but I'm telling you, I nearly cried. I've never been so happy with a product in my life. Highly, highly recommend giving these a try if you've got stubborn plantar warts.