Every painting project goes the same way: the paint goes on quickly, and the regret shows up at the edges. The difference between a professional finish and a hobby finish is not the brush. It is the preparation — filling the holes, sanding the patches, and taping the trim before the first drop of paint.
The order of operations is fixed: clean the walls, patch the small holes, sand the patches flat, wipe the dust, and tape the edges. Then cut in along the ceiling and corners with a brush, and roll the open areas in overlapping strokes. A second coat is not a luxury; it is the coat that covers the roller marks.
Two habits keep the job honest. Remove the tape while the paint is still slightly soft, so it peels clean instead of pulling the paint. And step back at the end of each wall — the view from a few meters shows what the close view misses. The room gets done twice: once with paint, once with judgment.