I have had bad experiences painting ceilings. I use good quality, semi-gloss paint and a roller. I always end up with lap marks and shiny spots. Any suggestions?
I suggest you try using flat paint specifically designed for ceilings. Semi-gloss tends to show lap marks and any uneven application. Flat paint is very forgiving and the better quality flat paints cover well and still can be cleaned.
You also need to practice your application techniques. With a roller evenly filled with paint, you should apply the paint in a “W” or “M” pattern over a 3 by 3 foot area. This spreads the initial, thick paint over a wider area. Then, work your roller up and down or left and right to even the coat of paint over the whole area.
Always try to paint from a wet edge so you new application blends in with the paint on the wall. When you lap new paint over dry paint, you run the risk of a lap mark. Finally, use lots of light so you can easily see how the paint is covering.