Signs of good fortune have been established in Hindu mythology since ancient times. Tibetan Buddhism has a group of eight symbols that are considered to be the oldest and most well known. These eight symbols include the Golden Fish, the Parasol, the Run, the Lotus Flower, the Conch Shell, the Infinite Knot, the Wheel, and the Flag.
Unalome & lotus. Enlightenment. The Unalome is originally a hindu symbol that graphically recalls Shiva´s third eye and it represents wisdom and the path to perfection. Full description and hi-res here: http://www.tattootribes.com/index.php?newlang=English&idinfo=7591
Om - This is a Hindu symbol and it represents the three gods Brahma, Vishnu and Maheswara. It is also the meditation symbol. It will increase breathing capacity and clean the respiratory system. If it is chanted in a particular manner, it will increase the concentration and leads to good health.
The ancient Celts didn't have tree signs, but they were skilled astronomers and most likely used some form of predictive astrology. We do know they had lunar calendars(e.g.,the Coligny calendar), although scholars disagree as to whether the start of the month was the new moon or the full moon. There is no agreement as to what symbols were used by the druids who created the calendars, but most historians think it is similar to the old Vedic/Hindu cosmological system.