For tiny debris, it really depends on whether it’s still floating or has sunk. The skimmer is great for anything sitting on the surface, but once leaves, dirt, or sand start sinking, the vacuum becomes way more effective. I usually brush the pool lightly toward the main drain first, then run the vacuum over the areas with settled particles. Letting the skimmer run at the same time doesn’t hurt, it’ll catch anything still drifting, but for fine stuff on the floor, the vacuum is your main tool. Adjusting the suction and making sure the water flow pushes debris toward the drain can save a lot of time too.