Well, it for certain that no one likes to get a blister. With some diseases like diabetes, blisters can actually become life-threatening very easily. If you are prone to blisters, cover the areas like your heel and toes with some type of bandage before beginning any long walk. Since walks are rarely timed events in the everyday world, stop from time to time and inspect your feet. If you notice reddening areas, try to find a way to cover and protect them from the friction that causes blisters to form.
Runners are more likely to have blisters appear and give them problems than walkers because running is often a timed event. When pain starts to appear, stop running or walking and inspect your feet. Unless you are into pain and suffering as a lifestyle, winning a race rarely will compare to the problems that blisters can cause for days and weeks.
Once the blister has made its appearance, you will need to treat it. If no treatment is possible right then, you should find a way to protect it. A bandage is the easiest solution. This may require tearing some material from your shirt to wrap the affected area. Try to stop the activity to prevent the blister from increasing in size or severity. A blister is a wound to your body. It is somewhere between a burn and a scrape or cut. This means take care of it.
The jury is out on whether to pop a blister or not. However, most people believe that draining it will allow you to better apply a salve or ointment to start the healing. If you do a self-draining, you will need either a really sharp knife, a pin, or a needle. It is best to sterilize this with a good rubbing alcohol. If this is not possible, use fire.
This is not perfect because some microbes can withstand hundreds of degrees without being killed. It is better than doing nothing. Most of the time this will do the trick. Heat the point of the needle or pin or the blade of the knife for several seconds. Do not go too long or the heat will travel in the metal and burn your fingers.
Pierce the outer skin over the bubble of the blister. Be careful not to pierce the tender flesh beneath the liquid. This will be excruciatingly painful and offer opportunity for infection to grow. Once the blister is drained, if you have some type of treatment to put on it, apply it now. Avoid things like salt or alcohol because these will just bring the pain up to the maximum. With or without treatment, cover the blister with a bandage. Try to find a way to get off of that foot or your feet. More movement will just further irritate the tender flesh of the blister.
Continue to treat the blister for a week or so until the dead skin falls away. If you remove it yourself, keep the bandage on until the skin has toughened enough to give strength and protection to the wound. With conditions, like diabetes, that make blisters a high risk, if the blister is more than about 1/2 inch in diameter, I would consult a doctor.
The final treatment is to buy shoes that fit correctly. At the same time, buy the type of shoes that are designed for the activity you will be engaged in doing. You will also want to get some socks that give additional padding in the areas that are blister prone like your heel.