Summarize:

You will need to do a little more advanced planning to watch the movie on separate televisions. Everyone will need time to get a copy of the movie to watch at their own home, either on DVD or with a streaming service. Pausing the movie will make it difficult to keep in sync with your friends, so it's best to keep the breaks to a minimum. Use the bathroom before you start the movie, and have your snacks and drinks handy as well. Click on your movie party conversation or group and hit the camera button, or the phone button if you're just doing an audio call. You may need to give everyone a few minutes to get situated before they will be ready to watch a movie. Decide beforehand if you'll be doing a video or audio call. You can start from the title screen, or you can pause at a frame and show everyone the screen to match it. This makes it easier to sync your movies if some people have different means of watching the film, such as streaming content providers. This is the tricky part. Have one person count for everyone, then hit the play button at the same time. With a little effort of fast-forwarding and pausing the movies, you can adjust the movie so you don't get an annoying echo over Skype. If you prefer, you can just have one person turn up the volume and mute the other televisions. You can also have everyone's Skype muted, and use the chat feature to talk to each other without interrupting the audio.
Make sure everyone has the movie you want to watch. Have everything you need nearby so you don't have to pause the movie. Call your movie party group on Skype at the chosen movie time. Queue up your movie. Count down to start the movies in sync.