The Five Elements
Wood, Fire, Earth, Metal and Water — and the two cycles (generating and controlling) that drive every Feng Shui cure. To weaken a bad energy or feed a good one, you work these cycles.
Growth, vitality, new beginnings, kindness, flexibility
Passion, recognition, expression, joy, transformation
Stability, nourishment, trust, groundedness, care
Clarity, precision, focus, discipline, righteousness
Wisdom, connection, flow, career, introspection
The two cycles
Add an element's “mother” to strengthen it; add its “child” to gently drain it (the preferred way to weaken a bad star).
Add an element's “controller” to suppress it — stronger than draining, but it can create new conflict, so it's the second choice.
The Five Elements and their two cycles (generating and controlling) are the core, near-universal grammar of Chinese metaphysics — Feng Shui, BaZi, and Chinese medicine all share them. This is a distinct tradition from Vastu's Pancha Mahabhuta (which uses five different elements — ether/air/fire/water/earth — and different rules). Colour and shape correspondences are the standard modern-practice conventions; the generating/controlling cycles themselves are classical.