Whats to do in case of smelly farts?

[don_equis]

Hi there freeones talk people, I take a lot of herbal suplements so when I fart them fuckers smell really bad. So what would be the proper etiquette when in a crowded enclosed space such as a bus, train or in a car and you feel your guts are about to bust and you either let it out in loud thunderous manner or the infamous silent but deadly?