Keep vegetation and trees trimmed around your system to prevent blocking the sun. The more shaded your system is the less efficient it will be.
Power wash or use your hose to wash off your solar system. Make sure you do not spray up into your inverters. Also do not use any chemicals or cleaners, as they will adversely affect your solar panels.
You can use a broom to clear the snow off. Or just clear any drifts in front of your system so the snow can just slide off the panels. Because of the dark color of the panels it quickly melts the snow in the sunshine.