To copyright a design, it is first important to make sure that the design is something that can be copyrighted. If the design is no more than an idea, then it cannot be protected. Alternatively, if it is a design of a method or technique of doing something, then it must be patented, not copyrighted. It is only possible to copyright a design if it is a work that can be perceived. Additionally, one must have a right to copyright the work itself, which one may not have if the work is derivative of another work or if it does not fit other criteria.
In areas that recognize a person's right to works that he or she has produced, it is usually not necessary to formally copyright a design. Any art, design, or other creative item that can be made tangible or physically perceptible is almost always protected by copyright in areas that recognize copyright with or without formal registration. If one can prove that one came up with and formalized the design first, then one's copyright is implied. Formal copyright registration can be helpful when attempting to fight copyright infringement, but it is not necessary.
Once the design exists, the designer's right over the design already exists. Registering the copyright only formalizes this right. To copyright a design formally, one must usually register with an office or agency related to this function. The precise agency will depend on the area. Often, a fee is involved.
It is more difficult to copyright some designs than others. For instance, it is not entirely clear whether one can copyright a tattoo if that tattoo is on a person's skin. Copyrighting a t-shirt design should not be problematic, but as these items can be made at home and may never come to the attention of the designer, it can be very difficult to enforce this kind of copyright. If one never knows that the copyright is being violated, then it can be impossible to enforce one's rights. It is easiest to go to court over copyright infringement if one knows that another party is making money off one’s design or releasing copies of the design publicly.
Even if one does copyright a design, there is no guarantee that fighting over the design in court will yield results. One must have a reasonable case and a good lawyer to win in a copyright suit. It may not even be worth going to court from a monetary perspective if the design is not worth significant amounts of money. Copyright is complex when contested, so it is a good idea to consult a lawyer if it is likely to be a problem.