I usually end up installing mine in a bathroom, because it has hard surfaces (counter and floor) and a lot of light, which helps with alignment and to spot issues. A dark garage next to the sander isn't a good spot
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Don't peel the backing off the glass until you're ready to mount it. Even then, sometimes a stray particle will end up sticking to it; use tape (supplied, or just plain cellophane on hand) to remove it.
I usually don't even bother with the tape they bundle with the package, unless it's one of those big swatches that can cover a whole screen and tear off like a hair waxer. A big roll of Scotch tape works fine.
After cleaning the screen, and right before application, liberally dust it off with the air duster. Keep the protector a safe distance away so as not to blast dust toward it and contaminate it.
Don't press down on the glass until you're confident it's dust free. When laid down gently, it's still relatively easy to lift back up and pick off any dust with tape, or fix an alignment issue.
Really, the bottom line is a clean environment, being able to spot issues and take care of them, and a touchless aid like the duster to take care of the last stray elements.
A phone protector is relatively easy. A tablet protector with the additional surface area ups the ante, but is still doable. Same procedure.