Protect your hands by wearing gloves, and be sure the ladder is level before climbing it.
Remove large debris from your gutters, beginning at major downspouts and working away from them.
Use a hose and hose nozzle to flush away small debris with water.
Apply an oil-based metal primer. Do not skip this step, as primer will help the paint stick and will make paint bubbles less likely to occur. Allow the primer to dry.
Apply the oil-based paint with a paintbrush. To get the best results, apply the paint within 48 hours of applying the primer.