Tying off skin tags at home is a method similar to the ones that doctors use and one of the most popular DIY remedies for removing skin tags. This process is also called Ligation. The overall purpose is to cut off the blood supply to the skin tag, so that its cells die causing the tag to fall off naturally. While this is considered a proven treatment, but you should avoid the pitfalls to get a successful outcome.
While there are many ways to remove skin tags, a lot of people consider using just a typical sewing thread to tie them off. This is a BIG NO! Because the thread is so thin, it can easily cut off into your skin and cause bleeding or even an infection. Dental Floss is what's considered relatively safe compared to all the other types of threads. It is thicker than the normal sewing thread and there are less chances that it would cut off into your skin. But you should still be careful while using it.
Everyone may not be comfortable with these methods as they can be painful at times. Doctors often use a process called Electrocauterization in which the skin tag is simply burned off. Devices such as Aven Buzz's Electrocauterization Pen can help you achieve that right at your home without spending hundreds of dollars at the doctor's office as these procedures are considered cosmetic and are not covered by insurance companies in most cases.