The answer to 'DIY lawn care' is that with some basic knowledge and the right tools, you can maintain your lawn yourself. Start by mowing regularly, keeping the blade sharp and cutting no more than 1/3 of the grass height at a time. Fertilize 2-3 times per year, using a slow-release lawn fertilizer, and be sure to water deeply and infrequently to encourage deep root growth. Aerate the soil annually to improve oxygen and water flow, and overseed bare or thin areas in the fall.
For more complex lawn issues like weed control, pest management, or major renovations, it's best to consult a professional lawn care service. They have the expertise and equipment to properly diagnose and treat problems to keep your lawn healthy and looking its best.