Part of the reason why people want to have body marks is because it is a way of self-expression. Since everything is transitory, naturally what you want inked on your body should be something that lasts and not just dependent on your mood or a particular incident in your life. It is exactly the same reason that most people turn to their zodiac signs for inspiration in choosing designs for their tattoos. A person's zodiac sign does not change with the passing of time because one's day of birth is permanent. Even then, there are people who opt to have tattoos based on the zodiac of other people important to them.
Anyways, the first on the list is the Gemini zodiac sign. Gemini are natural extroverts and are there before very alive when it comes to dealing with the people around them, they adapt well and communicative. A popular Gemini tattoo is the glyph which looks like the numeral II. A simple representation will use black ink or using the Gemini zodiac color yellow. A variation design would show the glyph along with other symbols like stars which fits with your over-all astrological theme. Many would choose to have other symbols associated with Gemini like flowers and gems. Another popular design associated with Gemini is the twins. This design is normally done on the arms, ribs or the shoulder blades because it is a large design.
Another popular hard to find zodiac tattoo design is the Libra tattoo design. A useful tip to find a special libra tattoo design is through large forums and not in search engines. Since Libra is represented by a woman blindfolded holding a scale, this is a natural big design and is fitting to be made on the arms or shoulder blades. A small representation of this tattoo would make it hard to appreciate.
Still, another popular zodiac option is the Capricorn tattoo design. Capricorn people are those born between December 22 and January 20. Capricorn combines water and earth. Capricorn people are dependable. The basic design lay out for Capricorn is the numbers 6 and 7 combined. This is an ancient design which looks great even when done in one color.
Whatever tattoo designs you want inked on your body you just make sure that the tattoo artist you go to is more than capable of rendering the art. It would be a waste of pain, time and money to have a sensational design only to be ruined by an inefficient artist.