I'm not the handiest of folks myself. Kind of a Klutz, actually. You should have seen some of the bonehead mistakes I made yesterday just trying to do some house painting!
The keys to this working for me, both for effect and finances, was knowing that I wouldn't be satisfied without masking, and paying a signmaker a few dollars to properly put the masking material on the panels. I first tried doing velvet on them with contact cement, and what a mess I made of that! Plus, it's hard to get a crisp edge with velvet. The Protostar product left a very straight edge which makes a lot of difference at the horizontal masking line on the screen.
Keep researching and find what'll work for you one way or the other. Masking makes a lot of difference in the enjoyment level, imho.
See ya. Dave
"High Fidelity audio has been like a dog chasing his tail. High Fidelity in my marriage has been much more rewarding because she knows where I sleep."