Wipe down your boots with a damp cloth to remove the thick mud from the surface. This will not thoroughly clean the boots, but it will make the problem more manageable by taking care of the excess mud coverage. Do this outdoors to prevent tracking mud into the home.
Apply a helpful cleaning solution to each boot. Many solutions can effectively remove mud and return the shine to a pair of leather boots. For example, sprinkle some baking soda onto a damp cloth and buff each boot thoroughly. For another natural option, try a cloth dampened with white vinegar. For a commercial option, try scrubbing each boot with saddle soap, sold in shoe stores. If one solution fails for you, try a different solution.
Scrub your boots with a clean, firm brush. Shoe stores sell specialized leather brushes, but any scrubbing brush will suffice. Scrub the entire boot to remove remaining dirt and deposits and to work the cleaning solution into the pores.
Wipe each boot with a damp cloth to remove the cleaning solution. Leave your boots outside in a dry location to air dry. Leather is highly porous and will not dry thoroughly with towels, so make sure to place the boots in an area with good air circulation in order to ensure optimum dryness and prevent mildew from forming on the leather.