When I applied my Hori, I worked from left edge to right edge. I first peeled 'some' of the red tab side of the film off. Just enough so I can align the protector to the left edge of the screen. Then I slowly pull the red tab side and used my fingers (or you can use a cloth-wrapped credit card) to push the screen protector down at the same time. I didnt get any air bubble at all. As long as you're doing it straight, slowly, in a dust-free environment, you should be fine. Also don't pull the entire red tab side of the film off completely, because dust will stick onto it if you leave it in the atmosphere too long. Pull the red tab film as you apply the protector onto the screen. Think of it as putting a band-aid on your wound. You pull the white film off from one side first, apply the sticky end to one side of the wound, then you pull the other white film off.