Summarize:

Make sure you are watching a scary movie with other people close by you. Invite more friends, family, or even pets if you're watching the movie at home. Talk to friends about the movie and whether or not they think they'll get scared. It can help to know that most people get scared by horror movies, whether they admit it or not, because that's the purpose of scary movies! If you're watching in a movie theater, make sure you have people you know on either side of you, if possible, without empty seats, strangers, or an aisle next to you which could make you feel less comfortable. You can even ask a friend if they're okay with you squeezing their hand or getting closer to them during scary parts. Most people are happy to help you feel at ease! Watch it with your girl/boyfriend; scary movies are often something that people bond over. See a movie in a room with the lights on, if possible. Get comfortable on a couch, chair, or the floor so you feel more safe. Avoid watching the movie while it's dark outside, or when you have to go to sleep directly afterwards. Watch a DVD during the day, or catch a matinee at a theater. Sit in a place next to the wall. You don't want to feel like something is behind you. You can even encourage watching a movie in a room of the house where other things are going on around you. This might help to distract you and remind you of reality during the movie. Wear a comfortable hoodie sweatshirt or other item of clothing that makes you feel warm and secure. Wrap yourself in a blanket if you want, or hug a pillow to your chest. Wear a hoodie to a movie theater as a way to stay warm in the typically cold space, stay comfortable, and even hide your face with the hood if you want to. Share a blanket with a friend to help you feel close to someone and be extra warm. Warmth and comfort will help the shivers or vulnerable feeling you get when you're scared. Get familiar with the movie you're watching before you see it in the theater or in someone's home. Knowing more about what will happen in the plot will help you be less surprised by the scary parts. Watch a trailer, and any other available scenes from the movie you can find online. You will already be prepared for the scary visuals that they often show in the trailers if you watch them beforehand. You can even listen to the soundtrack beforehand if it's available online. Do a happy, simple activity during the day while you listen to it and it won't seem threatening. The soundtrack often makes scary parts of the movie much scarier, but not if you take the fear out of the music ahead of time. If you've already seen the movie, you can still refresh your memory by reading or watching content related to it, or just know that you will likely be less scared by something you've already seen.
Watch with friends. Watch in a well-lit, comfortable place. Get a blanket or hoodie. Read about the movie.