Leave clippings on lawn. They provide free turf food and are best left on the lawn. Mow when grass is dry, preferably between the late afternoon and before the evening dew. Collect and remove clippings only when they are visibly heavy. Keep those mower blades sharp.
Sharp blades produce a clean, uniform cut.
They also limit damage to the leaf blade, reducing water loss and opportunities for fungal disease infection. Vary your mowing pattern. This reduces soil compaction.