To measure your dog's sock size perfectly, start by spreading the paw on a white sheet and tracing its outline using a pen or pencil. Once done, measure the widest points horizontally and vertically along the tracing. Alternatively, you can also wet your dog's paws and get an imprint on a white sheet. Again, like in the tracing method, measure the widest points, and you're good to go. However, it's important to note that you should add at least half an inch to both measurements (horizontal and vertical) to ensure the socks fit your canine perfectly.