The recurring backbone is usually Coriander Seed and Cumin Seed: coriander brings citrusy warmth, while cumin brings earth and depth. From there, masalas branch out.
Sour masalas often use Amchur or anardana. South Indian blends such as Sambar Powder and Rasam Powder may include Fenugreek Seed, curry leaf, chiles, lentils, black pepper, and a pinch of Asafoetida. Bengali panch phoron uses whole cumin, fennel, mustard, nigella, and fenugreek. Marinade blends like Tandoori Masala often lean on red chile color, paprika, garlic, ginger, cumin, and coriander.