Clean, Clean, Clean...
Gutters fill with leaves and other debris and become clogged especially if you have trees nearby. Just ask gutter installers. They'll tell you that you should clean your gutters a minimum of  twice a year, once in the spring after the trees bud out, and once in late fall after the leaves drop. Now in the Northwest if you have fir or cedar trees, it becomes every quarter. That's a lot of trips up and down a ladder, and few of us are that disciplined. But clogged gutters overflow, soak the siding and cause paint to peel, dampen basements, erode foundations, splash against the building and rot wood. Look for early signs of clogged gutters, erosion in the flower beds or stain/streaks on the gutter and fascia.