Keep the headlight switch well WD40'ed. My headlight main beam has started playing up, so much so I though a bulb had gone so bought some replacements this afternoon, only to have the thing light up again in the dealers car park! I'll strip the switch tomorrow and clean the contacts. The switch is open forward, so even with the brush guards on, rain and road crud will drive straight into the switch. Maybe make a Sugru shield on the button to stop this happening.
Tim