Remember very thorough cleaning of the screen is essential to remove any and all traces of oil, finger print stuff and everything prior to application. Carefully use a can of compressed air immediately prior to application and AFTER thorough cleaning as the glass becomes a huge magnet for fine dust particles. Have very good tangential lighting to even see these dust particle intruders! I spent way more time cleaning my screen and back of the phone than ever before to avoid any issues with "lack of adhesion" around the home button and ear microphone than ever before.
Result....a perfectly adhered Crystal Film application. Definitely start at the top, not the home button end, unless you're perfect at these installations. Like a previous poster correctly stated, who was right on about this....VERY careful use of the squeegee and microfiber cloth helps a lot post installation to ensure perfect sticking of these films without damaging the home button or speaker areas of these films. Those areas are delicate to install and require a careful touch, gently massaging the newly installed film inwards towards the center of the home button and speaker.
Be gentle, thorough and NOT too aggressive when massaging these critical areas with the microfiber cloth or the films will pull a bit and "show".