Summarize this article in one sentence.
One of the key aspects of your alien characters should be how they look. To make your aliens seem convincing and interesting, you should try to be as detailed about their physical characteristics as you can. Because you are writing fiction, you have the ability to create as many strange and interesting details about your alien characters as you like. Avoid using familiar images or descriptions of aliens and use your imagination.  Think about how the aliens walk and move their bodies. You should also think about how their bodies are proportioned. They do not necessarily need to walk on two legs and have limbs like humans. They may have physical characteristics that have evolved due to their world or environment. For example, maybe your aliens have antennas on their heads because they can feel shifts in the wind in their world, allowing them to hunt for food more effectively. You should also think about whether there are different genders in the alien world and how the bodies of different genders appear. You do not have to be limited by male or female genders. Maybe the alien race has a third gender that is asexual or a combination of male and female genders. Avoid creating the alien characters in the shadow of humans and get creative with language, thinking beyond English or other languages found on Earth. You may decide to create an alien language that may then be translated with the help of a computerized device or an implant in the human brain. Your alien race may also communicate in other ways besides language or words. Maybe they use their antennas to send messages to each other or have the ability to communicate through telepathy. Perhaps they use a system of body movements to communicate. The humans in your story may also be key characters in the narrative, so you should create humans that are just as interesting as the aliens. Your main character may be a human with a special ability or a unique characteristic. Creating nuanced humans in your story will make it that much stronger. For example, maybe your main character is a human who has been gifted with the ability to read minds. This human is then able to access the conversations of the alien overlords, who have enslaved the human race. This ability could allow the human to save the humans from the aliens and become the hero of the story. Once you have sketched out your characters, you should identify the central conflict. Doing this will give the story an end goal and frame the narrative for the reader. It will also allow you to use your characters to build tension in the story. The central conflict may be between your alien characters or between an alien character and a human character. For example, maybe the central conflict of your story is that aliens have taken over the human world because their planet is no longer habitable. This alien invasion may then result in a human hero who tries to fight the aliens with a special ability and help from other humans in his community. Or, maybe the central conflict is that humans have enslaved aliens who have crash landed on their planet. The humans may then try to hide the aliens and experiment on them. This may then result in one alien who tries to oppose his human captors.

Summary:
Describe the physical characteristics of the aliens. Create an alien language or way of communicating. Give the human characters special abilities and unique characteristics. Determine the central conflict of the story.