When I bought a new pair of boots everything was perfect except they were so hard on the bottom. I bought them knowing I had to get some kind of insole for padding. I went looking for something cheap, thinking I would just get some padding. Instead I found these Dr. Scholl's Massaging Gel Insoles for a relatively cheap price. And they are so much better than the cheap foam pads.
These gel insoles have made such a great difference in the feel of my boots. I can now walk for a much longer time before my feet start to get pressure points. This is because of the shape of the boots, not the insoles. I think if I put these gel insoles in my tennis shoes they would be incredible. In the boots however, I still get pressure points on the ball of my foot after walking for a couple hours.
The gel does not really massage because the gel is on the bottom on the insole. All it really does is give a nice, squishy padding to walk on. After walking for a while, the pad in one boot started moving and slipping. I just wiggled my foot around and they went back into place. I did have to cut the insole to fit the boot, but they have size guides to help get the size right.