Big rule of thumb is to affix the screen protector right on the first try, with a minimum of fuss. Clean off the screen, unwrap the protector, peel the backing, apply with the credit card, voila. If you can manage that in less than a minute, you probably won't have to worry about dust particles or anything. The dust gets in there if you remove and reapply the protector over and over again, trying to get it right.