How to Treat a Foot Blister

Blisters on the feet can be not only painful but debilitating, so follow these steps for treatment.
Steps

Clean around the area of the blister with warm water and a little tea tree oil.
As a general rule of thumb, if the blister is not too painful do not do anything. If it is painful and filled with liquid, you can do something about it.
If the blister is causing discomfort, sterilize a needle with alcohol and/or boiling water, and carefully insert at the edge of the blister and allow it to drain.
Do not remove the loose skin that covers a blister, as this opens it to infection.
Cover the blistered area with a plaster if it is open. If not, allow your foot as much air as possible.
Avoid tight shoes which rub and chafe.

Tips
To avoid blisters altogether use "Friar's balsam" and foot tape over the area where rubbing occurs. Be sure not to allow the tape to fold - it is better to stretch than to fold it - but if you do allow it to fold, then cut the tape down so that it is the same thickness all over.

Warnings
If a blister has excessive amounts of fluid draining from it, starts to smell, or becomes red, see a doctor immediately.
Do not use a match to sterilize the instrument that you will use to pierce the blister --fire will oxidize any coatings on the metal and leave black, sooty particulate that can cause an infection.