Ok some of you may not like this tip and some of you may already know this one.
I hate doing strips and I really hate cutting them on outside of the windshield.
What I do is I have a sixty inch roll of 5% film on a film handler for strips only, pull down 7-8 inches (depending on the size of the strip you need) and cut it of the handler so both top and bottom of film are straight edges, film should be now 60"x8" or so, clean the inside of the windshield. With the mirror removed(depending on vehicle) peel the liner off the film and go right inside the car with it, set the film so both top side corners of the glass are covered with same amount of film, then push the water out with a squeegee and cut aruond the mirror bracket. If top sides of the windshield are even the film will be even. If one side of the film is higher than the other side the strip will be crooked. It might sound like a pain the azz but its very easy to do and no measuring is needed, once you get used to it it should take 2-3 minutes to do almost any strip. Any window thats need shrinking is easy also, just move fingers to the side and shrink them horizontal on the inside. Super easy to do but Im not good at explaining things. I hope some of you give this a try and tell me what you think, it takes a little getting used to but its real time saver.