I just put the stuff on my car and to tell the truth, it was very, very easy. I made patterns from a brown paper bag. Made two of them 'cuz my car is not the same on both sides. (The story is that the mold was pulled from an original and none of them were the same, side to side).
Then I had to attach the pattern to the Invincishield material so I could cut around it. That presented a problem as tape will not stick to the backing. I ended up using 3M spray on contact cement which got enough of a grip for me to stick the patterns on and cut them out. Since you are working from the "back" of the pattern (you're on the back or the side that will attach to the car) you need to make sure the pattern is facing the correct way before you cut. Naturally my first cut out was facing the wrong way! Once I figured that out it went very fast, about 10 minutes start to finish.
I made mine 12" high which put them just below the point where the compounding would have gotten severe. When I put them on, the compound curves were evident and I thought "Oh crap" for a minute, but I just kept squeegeeing and pretty soon everything took shape. They recomend that you have a little denatured alcohol around to help stick down the edges. I guess the alcohol displaces the water and makes the stuff stick. I used the alcohol in a couple of iffy places and everything then "Stuck". I may go up to the shop in the morning and find the things laying on the floor, but I don't think so. So now I am an expert!
Bish