In some forms of hoodoo and folk magic snakeskin is dried and then ground into a fine powder, sometimes referred to as "snake dust." You can either do this, or you can use a full piece of snakeskin. It is believed that rubbing a bit of snakeskin on your hands can keep you from dropping things. Another legend is that if you carry it in your pocket, it will bring you good luck.
Try using the shed skin in spells related to protection. You can place the skin around your property, guarding the perimeter, to keep these people away.
Consider using a snakeskin or a piece of one in a charm bag with crystals and stones used for protection.
For transformation magic You might want to try using snakeskin in a spell to help you get over something, allowing you to move on from past mistakes, or shed a bad relationship or unhealthy habit. Make a poppet to represent yourself and fill it with little things that remind you of the baggage you're carrying with you – letter clippings, wadded up photos, anything small enough to fit.