The key text that we now generally referred to as I-Ching is actually called Zhou-Yi (周易） written by an Emperor previously in jail. There were however two other previous texts based on or inspired by the 64 hexagrams. They are called GuiCang-Yi （歸藏易） and LianShan-Yi (連山易）. They are both lost, though in 1993, a bamboo text was discovered in China on the former.
In risk of oversimplifying things, Zhou-Yi is more towards a relation between the Sky (Male symbol) and Man, where the other two being towards an emphasis between Earth (Female/Mother symbol) and Man. And Taoist meditation and Feng Shui have more affiliation with the two lost I-Chings.
An important symbolism developed from GuiCang-Yi （歸藏易） is a concept called 12 Developing Hexagram (十二辟卦). These are also called the 12 Information Hexagram (十二消息卦). They symbolize development patterns and provide information. Diagrammatically it is like this:
The question is: How is the 12 Developing Hexagrams related to Taoist meditation? Or the question can be phrased more fruitfully as: How Taoist meditation makes use of it?
If we start with Qian (乾 - all solid lines), moving clockwise we have 6 step increments of broken line (signifying Yin 陰) till we arrive at all broken lines Kun (坤); which if we continue to move clockwise in 6 step increments of solid lines (signifying Yang 陽) till we arrive at all solid lines again.
The natural physical development of a human body is from life (Qian 乾) moving in 6 steps towards death (Kun 坤). To make matters more interesting, these 6 steps can be divided into age-segments, different for male and female:
1. For male: in increment of eight from age 16 (puberty): 0-16 (full), 17-24 (one broken line), to 25-32 (two broken lines), to 33-40 (three broken lines), to 41-48 (four broken lines), 49-56 (five broken lines), above 56 (all broken lines: beginning to have no more productive ability!)
2. For female: in increment of seven from age 14 (puberty), and likewise (interested readers can do their own math) ending in above 49 being the start of menopause.
In Taoist meditation (or Neidan 内丹), it is moving back the cycle. The classic said before one reaching the state of Kun (坤), one still have a good chance to move backwards: meaning increasing the solid lines (step by step) reaching ultimately at the state of Qian (乾). According to Taoist classics, it is both a physical (chi-generation, bone/muscle/internal organs training) as well as mental or psychological training (Tao, morality and enlightenment).
Final advice from the classics: Don't delay, act now, before it is too late!