I have just spent 5 days painting 75% of the downstairs of my house using the RL suede paint. I painted professionally for a year and will give you some tips on what I found. 1. The first coat of paint is really not important as to how you apply it. I used one wall to experiment on. I found that even if I really messed up the first coat(within reason) I could cover it all with a properly applied second coat. This means put on the first coat like you would a normal paint job. Forget about the every 18". That is teadious and unnecessary. I even painted a whole heavily windowed 10 x 14 with just a brush for a first coat.
2. To apply the second coat make sure you have an excellent 3" brush. Don't get the cheap stuff. 3. Once you start a wall you must not stop at any point. Don't talk on the phone or watch TV or do anything but finish what you started. Work fast. If you run out of paint half way across the wall, forget about it, you will have to do the whole wall over.(Did I mention this paint is hard to work with?) 4. When you apply the 2nd coat, use alot of paint on the brush and overlap frequently. Work about a 12 to 18 inch section from top all the way to the bottom. then go back to the top. But work fast, once the paint dries you cannot, for the most part, do touch-ups. 5. Every now and then back away and look at the patterns you are making(EVERY MINUTE OR SO). You want to smooth out any globs of paint and use a very light touch with the tip of the brush. Otherwise you will have dark streaks all over the wall where the brush head hit. Not pretty! 6. Have some basic artistic ability. It takes much work, but the house does look great(Fawns Leap)