How can I avoid dust and bubbles when installing window film?
From my days installing car film, I have two basic suggestions. 


Get off the floor. You can't work down there without dust being blown into your workpiece every time you move. Get up on a table in a room without a lot of human or pet traffic, where the air remains still. Most installations are on the window in a wall anyway. 
Use plenty of solution. You don't want things drying out before you have a chance to squeeze out all the air bubbles. They shouldn't be difficult to move if you have things wet enough. Using more will also tend to flush out dust. Per one comment on the product page: "1/4 tsp of tear free no conditioner added baby shampoo per 1qt of water works better than the $3.97 per bottle of Gila spray."