Quite simply, you can copyright intellectual property simply by creating it in some tangible and real form. You cannot copyright an idea in your head, so to have copyright protection for an intellectual property you have to make that concept real and more than simply an idea. This means that you have to create something, by writing down a story, filming a movie, recording or writing down a piece of music, or otherwise making your creative work a reality in order to copyright it. Although you can copyright intellectual property simply by creating it, you may wish to register a copyright in order to gain greater legal protection for your work.
There is a fairly common misconception regarding the creation of a copyright and how an intellectual property can be protected by copyright. Many people believe that to copyright intellectual property, the creation must be registered or otherwise presented to some government agency. International copyright law, however, dictates that you copyright intellectual property at the moment that you create your work. All you have to do to establish a copyright on a work of art or similar intellectual property is make it real in a tangible form.
You do not even need to include a copyright mark to copyright intellectual property that you create, though this is often recommended. By including a mark such as © with the date and your name as copyright holder, you can indicate to others that your work is under protection as an original intellectual property. Legally, you do not have to do this, but it can make it easier to later prove something was used without permission; without this mark, others can potentially claim ignorance to copyright protection on your work. Once you copyright intellectual property you have created, simply by creating it, you may also want to register your copyright for further protection.
Though you copyright intellectual property the moment you create it, you may find it difficult to later prove the date when you created that work. This can be important in legal situations that may arise regarding a work that is derivative of something you have created. You can typically register your copyright with a government or private agency that will accept a copy of your work and indicate the date on which you registered the copyright. In the US, you can register a copyright with the US Copyright Office, though in other countries you may need to register with a private company rather than a government agency.