Blisters:

Common causes of blisters include friction and burns. If the blister isn't too painful, do everything possible to keep it intact. Unbroken skin over a blister provides a natural barrier to bacteria and decreases the risk of infection. Cover a small blister with an adhesive bandage, and cover a large one with a porous, plastic-coated gauze pad that absorbs moisture and allows the wound to breathe.

Don't puncture a blister unless it's painful or prevents you from walking or using one of your hands. If you have diabetes or poor circulation, call your doctor before considering the self-care measures below.

To relieve blister-related pain, drain the fluid while leaving the overlying skin intact. Here's how:
Wash your hands and the blister with soap and warm water.
Swab the blister with iodine or rubbing alcohol.
Sterilize a clean, sharp needle by wiping it with rubbing alcohol.
Use the needle to puncture the blister. Aim for several spots near the blister's edge. Let the fluid drain, but leave the overlying skin inplace.
Apply an antibiotic ointment to the blister and cover with a bandage or gauze pad.
After several days, use tweezers and scissors sterilized with rubbing alcohol to cut away all the dead skin. Apply more ointment and a bandage.

Call your doctor if you see signs of infection around a blister — pus, redness, increasing pain or warm skin.

To prevent a blister, use gloves, socks, a bandage or similar protective covering over the area being rubbed. Special athletic socks are available that have extra padding in critical areas. You might also try attaching moleskin to the inside of your shoe where it might rub, such as at the heel.

Shoe-shopping tips
Remember the following when you shop for shoes:
Shop during the middle of the day. Your feet swell throughout the day, so a midday fitting will probably give you the best fit.
Wear the same socks you'll wear when walking, or bring them with you to the store.
Measure your feet. Shoe sizes change throughout adulthood.
Measure both feet and try on both shoes. If your feet differ in size, buy the larger size.
Go for flexible but supportive shoes with cushioned insoles.
Be sure that you can comfortably wiggle your toes.
Avoid shoes with seams in the toe box, which may irritate bunions or hammertoes.