Summarize:

Most fractures of the toes, including the pinky, are stress or hairline fractures, which are tiny cracks in the bone's surface. Stress fractures are often quite painful and involve some swelling and/or bruising in the forefoot area, but they don't cause the bones to look crooked, crushed, mangled or sticking out of the skin. As such, simple stress or hairline fractures are appropriate to tape, although more complicated fractures need different medical procedures, such as surgery, casting or splints. See your doctor for an x-ray of your foot if the pain doesn't get significantly better within a few days. Stress fractures can be difficult to see on x-ray if there's lots of swelling. If there is lots of swelling, your doctor may recommend a bone scan to identify the stress fracture. Stress fractures of the pinky can occur with strenuous exercise (lots of jogging or aerobics, for examples), improper training techniques at the gym, trauma from stubbing the toe or dropping something heavy on it, and severely sprained ankles. Any time you're dealing with a body injury by using some sort of supportive tape, it's best to clean the area first. Cleaning the area will remove bacteria and other microorganisms that could potentially cause an infection (such as fungus), as well as any dirt and debris that can prevent the tape from sticking well to your toes. Regular soap and warm water is usually sufficient for cleaning your feet and toes. If you really want to sanitize your toes / feet and remove most of the natural oils, use an alcohol-based sanitizing gel or lotion. Make sure to completely dry your toes and the spaces in between before any using gauze or tape. Once you've identified that your pinky toe is broken, but not too severely, then the first step of buddy taping is to put some gauze, felt or piece of cotton between your little toe and the toe next to it (called the 4th toe). This will prevent skin irritation and any potential blistering as your 2 lateral toes are taped together. Preventing skin irritation / blistering reduces the risk of developing an infection. Use enough sterile gauze, felt or cotton balls between your 4th and 5th toes so that it doesn't easily fall out before securing it with tape. If your skin is sensitive to medical tape (maybe it gets irritated and itchy from the adhesive), then wrap the gauze completely around your 4th and 5th toes and cover as much of the skin as possible before using tape. After you've placed some sterile gauze, felt or cotton between your toes, loosely tape the 4th and 5th toes together with some medical or surgical tape made for applying to the body. This is the buddy tape method, as you're essentially using your 4th toe as a splint to support, stabilize and protect your broken pinky toe. Tape from the base of the toes up to about 1/4 inch from the top of the toes. Wrap the tape around twice using 2 separate strips so it doesn't get too tight. Wrapping the tape too tight will cut off circulation and turn the ends of your toes a purplish-blue color. Your toes will also feel numb or tingly if you've wrapped the tape too tight. Reduced circulation to your toes also slows down the healing process, so make sure to buddy tape the toes together firmly, but loose enough that blood flows normally. If you don't have any medical or surgical tape (sold at regular pharmacies), then duct tape, electrician's tape or small (narrow) Velcro straps can work also. Most simple (stress) fractures of the toes take about 4 weeks or so to heal properly, so plan on buddy taping for the majority of that time. Buddy taping toes together to give support and promote healing is an ongoing process, not just a one-time procedure. If you shower or bathe every day, then you should re-tape your toes on a daily basis because wet gauze or felt is less effective at preventing blisters and the water starts to dissolve the adhesive glue on the tape. As such, remove the old tape and gauze after bathing and use dry gauze or cotton and fresh tape after your feet are clean and dry. If you bathe every other day, then you can wait an additional day to re-tape your toes unless your feet get wet from some other reason, such as getting caught in a rainstorm or flood. Using water resistant medical / surgical tape may reduce the frequent need to re-tape, but any time the gauze / cotton between your toes gets wet (or even damp) you should redo it. Remember not to use too much tape (even if it's loosely applied) because you may not be able to fit your foot into your shoes properly. Too much tape also triggers overheating and sweating.
Determine if taping is appropriate. Clean your feet and toes. Put some gauze or felt between your toes. Tape your pinky and 4th toes together. Change the tape and gauze daily.