In an introductory note to this chapter, the Kitzur Shulchan Aruch writes that most Jews are already familiar with the prohibited labors of Shabbos and that he is only addressing common situations with which people may not be familiar. Clearly, the laws of Shabbos constitute an area requiring much greater study than this email alone will allow.
80:39 One may not shake a (new – OC 302:1) black garment in order to remove snow or dust. (Bi’ur Halacha 302:1 s.v. min hatal permits one to shake off snow. Mishnah Brurah 302:6 permits one to have a non-Jew remove the dust from his clothes.) One may remove feathers by hand, though some authorities are concerned about this as well.
80:40 If a person gets mud on his leg or on his shoe, it may be wiped off using an object that one is permitted to be handle on Shabbos. Alternately, he may wipe it off on a wooden beam but not on a (stone – MB 302:27) wall or on the ground. (There’s room to be lenient, especially in the case of a wall - Mishnah Brurah 302:28.) In a case of real need, such as if a person steps in excrement, if there is no permitted object available, one can wipe it off on a wall, and if there’s no wall, he may even use the ground. If water is available, he may wash the shoe so long as it's made of leather, since this would not be considered laundering unless one rubs one side against the other as people do when laundering. One may not, however, use a knife to scrape mud or excrement off of a leather shoe. Formerly, people had an iron bar in front of their houses in order to clean off their shoes. If it was sharp, it could not be used on Shabbos, otherwise it was permitted.