Dear Lifehacker, I know that it's a good idea to keep a screen protector on my phone, especially if I want to sell it later to offset the price of my upgrade. The problem is, there are a lot of protectors to choose from, and even after I've got one, how do I apply it without messing it up? Signed, Needs Protection Dear NP, A lot of people use screen protectors on their mobile device these days. One of the most common questions people have is ''what is the best way to apply them?' This question is also followed quickly by, "How do you keep thing from getting stuck to the bottom when you are putting them on?" The video demonstration above answers both question. But first, let's start with the basics. What are screen protectors and what are they good for? Screen protectors come in many different shapes, sizes and styles. It seems that no matter what type of device, be it tablet, iPhone, Android device or feature phone there is a screen protector you can pick up to help keep the screen looking new. Screen protectors in the general sense are mainly used to protect the screen from scratching, however they have evolved into other uses as well, including screen privacy, and anti-sticky stuff (fingerprints, makeup, etc). But how do you choose the right ones for you? What types of screen protectors are there? Regular Screen Protectors: Usually the lowest cost and come in the largest number per