Measure to determine the dimensions of the stump. This will allow you to design a carving that suits the size of the stump.
Mark the design on the stump, using a marker. Do not carved narrowly designed parts, as there is a risk of the wood splitting and breaking.
Remove large chunks of the stump aren't not needed, using a chainsaw. This should leave a stump that reflects the overall shape of the carving design. Do not carve intricate designs with a chainsaw.
Whittle the remaining sections of wood to match your design, then sand any rough edges and splinters. Employ coarse sandpaper to retain a rustic look to the stump or fine sandpaper to give a smoother finish.