What is best method to apply paint on primed wall to get high quality streak free results?

The best method to achieve the results you are looking for would be a professional sprayer. You can rent these from your local tool rental store. Keep in mind the prep work is very important. Make sure the wall(s) are thoroughly cleaned, dust free, free of defects. Protect all areas and surfaces that you don't want painted to a ';high quality streak free finish'; :) The best time you can spend is certainly on prep. Your local tool rental store will assist you in proper operation of the equipment, make sure to tell them the type of material you will be applying, Good luck with your project and happy spraying!What is best method to apply paint on primed wall to get high quality streak free results?
Use a good quality roller that is suitable for the kind of paint you are applying.What is best method to apply paint on primed wall to get high quality streak free results?
good 3/8';s roller nap and make sure you roll it out, you get your streaks from uneven walls and too much pressure applying it. don't use a pole and roll with your hand meaning just use the roller frame, naturally if you got really high ceiling then you'll need the pole but being up close you'll see your streaks and holidays. Use a quality paint that does'nt dry the minute you hit the wall, if you do add a LITTLE water to slow down your drying time, good luck, you can do it you don't need the hassel of spraying, if it was a new home o.k. but a repaint, not worth it.