The answer to 'how to maintain shingles' is to regularly inspect and maintain your roof to ensure the shingles are in good condition. This includes cleaning debris, fixing any loose or damaged shingles, and applying a sealant or coating to protect the shingles from the elements.
It's recommended to inspect your roof at least twice a year, in the spring and fall, to catch any issues early. You can do this yourself or hire a professional roofing contractor to inspect and maintain your roof. Regular maintenance can help extend the life of your shingles and prevent more costly repairs down the line.