Start with a clean surface, cover edges with tape to avoid burning through. Sand with 1500 to 2000 grit, remove just enough clear to level flat. Clean and change sand paper often. Then start buffing, I like to use miguires #85 with a wool pad. Buff with light pressure and around 1500 to 1700 rpm, use just enough compound to lubricate the surface with out drowning and slinging crap every where. Clean pad and surface often. When all the sand scratches are gone and it it 95% perfect then clean up compound and switch to miguires #83 and a foam pad, slow down the buffer 1200 to 1400 rpm and finish the shine and remove all swirl marks. Remove tape and clean up compound the step down to soft foam pad and use miguires #9 to finish up any remaining swirl marks. Throughly clean all compound out of all cracks and door jams before it dries. Then in a couple months, wax. Make sure you spend enough time with the wool pad and the #85 to remove all the dull spots and sand scratches as the other 2 steps don't do much to remove scratches. Check your work with different light sources and look at it at different angles. A complete car can and will take alot of hours, I normally spend 12 to 15 hours on one car. Unless it is a show car then you can double that or more.