I wanted to highlight some of the spices used in Indian cooking-
Garam masala- (hot masala powder)- well, the recipe differs from region to region and I am pretty much sure that you will get a decent brand from your local market- Garam Masala is a culmination of various spices like- cumin seeds, shahi jeera or black cumin, cinnamon, black pepper, cardamom (Green, black and brown varities), nutmeg, coriander seeds, fennel seeds (may contain traces of garlic powder, ginger powder, turmeric powder, red chilli powder- depending upon the brand). Using Garam masala will add good authentic Indian flavor to your food.
Another powder which I most commonly use is the hot curry masala powder. This is similar to garam masala but has a different and strong flavor than Garam masala- This masala not only contains similar spices to that of Garam masala but also asafoetida, mustard seeds, caraway, coriander seeds and brings in a little bit of color to your food (because of turmeric).
Corriander powder- I love using this one and tend to add it to almost all my cusine because of the exotic flavor it brings to the food.
Turmeric powder- Bring that lovely color to your food with turmeric powder- it is really good for health!
To get a tangy taste to your recipe you can even use amchur powder (made from dried, ground mangoes)- A dash of this powder in vegetables wouldn't hurt and gives a nice tangy flavor-
Bay leaves gives you an exotic aroma to any gravy or rice and I do use it a lot along with green cardamom-
I love adding a bit of Ajwain seeds (Carom seeds) for medical reasons- It helps reliving gas from your stomach-
There are many more masalas that can be used to bring a good flavor- I have often seen that sticking to the basic ones really helps and you can keep trying out different ones till you feel a particular combination gets your taste buds tingling! There is no hard and fast rule for the masalas- My mom always used to tell me- Keep it simple for the real flavor to come through :)