K.H.
I looked around a little on this subject and as far as I can tell, there is nothing that will prevent skin tags.
Some people have used iodine and said that it works when applied twice daily. Supposedly it takes anywhere from a couple of days to a couple of weeks and is painless, but mostly people are just using sharp scissors, a nail clipper or a Styptic pencil to remove them and using pressure to stop the bleeding.
Some have had success with wart and mole removal products as well.
Now, I don't know if I'd have the guts to chop something off my body personally, but if you decide to go for it make sure you use an antibiotic creme afterwards.
Good luck!