Keep your blades sharp. A dull knife is difficult to push through wood, requiring additional force. When the wood finally gives, the blade keeps going.
Always push the blade away from you, and constantly consider where the blade will go.
Keep your fingers clear of the blade at all times.
When splitting wood with a knife, do not hammer on the back of the blade. This weakens the attachment to the handle and deforms the blade.
Close a pocket knife when it's not in use or when you are carrying it.
Keep all blades away from heat. Heat will remove the temper, softening the blade. A soft blade will not hold an edge, making it nearly impossible to keep it sharp.