Letting wounds heal on their own is the recommended course of action. Trees have perfected efficient methods for this over millennia. Woody plants can't repair their own torn tissues like humans or animals can. Instead, they use layers of cells to seal off wounds and stop the spread of damage.
Do not prune in the autumn. When the temperature drops below freezing, new growth stimulated by pruning cuts will be lost. As summer draws to a close, trees and shrubs, slow their rate of photosynthesis, relying instead on stored energy for the new growth that occurs in the fall.
Treating a wound should only involve removing any loose bark or wood. Keep the wound open so the tree can start the callus development and healing/sealing over the process. It was previously suggested that "scribing" a wound in an elliptical form would promote better circulation of blood, lymph, and other healing factors.
If the damage isn't too severe, you can help the tree heal by trimming away any dead or damaged branches, patching torn bark, or smoothing off rough areas surrounding the wounds. Losing a single large branch is usually manageable for an established shade tree. The broken branch needs to be cut back to the main trunk.