1) Use a horse hair brush to wipe away any leftover residue from the winter (dust, dirt, salt, etc).
2) Wipe down your boot or shoe with a leather soap that will clean and moisturize the leather.
3) Using circular motions, work in some polish to get a nice looking shine.
4) Finally, use the horse hair brush to buff the leather.
Watch the following video to get a better idea of how to get those dull looking shoes, looking brand spanking new.