Practice. We dont get air bubbles when we laminate... If we're not paying attention there might be 1-2. Take a pin, not a knife... and pop it in the center. Then work your way from out to in, and the bubble will go away.
The bubbles wont go away on their own... you need to pop them. Once you get used to applying perf with laminate, you shouldn;t get much, if any bubbles though.