Many people like to design a tattoo rather than picking out an already-made tattoo design so that they can have a customized tattoo which is also deeply personal. Anyone can design a tattoo, but there are a few things to keep in mind when thinking about a tattoo which can be used to create a more effective tattoo design.
The first step is thinking about the elements you want to include in your tattoo design. You may want to sit down and think about what the tattoo means to you, and which elements would represent that meaning, or you may want to rework an existing design, such as a family crest. If you see a tattoo which appeals to you, you may want to file the look and feel of the tattoo away in your mind for future reference, but don't copy a tattoo. People who design their own tattoos or work with an artist to create a custom design do not appreciate seeing their work duplicated on others!
It may help you to sketch out some of the elements of the tattoo design on paper. If you're not a very good artist, you can still design a tattoo with some artful use of tracing paper, although you may find yourself adjusting the design to meet your needs after you have traced it out. Start with a basic pencil or black ink for your roughs.
Once you have an idea of what you want, think about where you want it. Placement of tattoos is an important consideration in tattoo design. If, for example, you want a tattoo which runs up your side, you can design a tattoo which highlights the natural curves of your body and flows with it, rather than one which looks pasted on. When considering placement, you should also think about size. As a general rule, the bigger a tattoo is, the better, because big designs will remain striking and bold after years on the body, while small designs can turn muddy and indistinguishable. You might want to ask a friend to trace the area of the body you plan to use for a tattoo site so that you know how much space you have to work with.
Once you have completed these steps, you can advance to working on the actual tattoo. Many people like to start with the linework, the part of the tattoo which will be applied first. Linework should be simple, clear, and bold, since it is just the outline. Details will be added later, so think plain, and remember that every wavering line will be replicated by the tattoo artist. It's a good idea to do linework in pencil, lightly sketching in the details, and then to go over the work in pen so that it stands out.
After you finish the linework, make a copy of it, and use the copy to flesh out the details you want, such as highlighting, shading, and color. You may want to be aware that the tattoo artist may recommend changes based on his or her experience, and sometimes it's better to provide rough hints of the type of detailing and color you want, leaving the precision work up to the artist. The artist may also have textural suggestions, such as shading in the background; you can reject these suggestions if they are not in keeping with your vision of the tattoo.
With your tattoo design and linework in hand, you can seek out an artist who will work with you. It's good to find an artist who likes your design and works in the style you are aiming for, to ensure that the tattoo is well-executed. You may need to shop around awhile, but it's worth it; after you design a tattoo, you might as well make sure that it looks as good as possible.