It's easy to make your own curry (an English word! Not Indian!) but if you want a truly outstanding flavour - you need to use FRESH ingredients.
Go to your local Asian supermarket and get (as a whole seed/root/fresh):
Coriander Seeds
Cumin Seeds
Fenugreek Seeds
Turmeric
Cloves
Garlic
Curry Leaves
Fennel Seeds
Ginger
Chillies
Red Pepper
Black Pepper
Anise
Cardamom
Cinnamon
Dill Seed
Nutmeg
White Pepper
If you are thinking Indian, add onion, garlic, ghee (clarified butter), water and tomato paste to make the sauce. In a dry frying pan add a combination of spices from the list above. It's fun - just sniff and add. Toast them for a minute or two to release their flavours and then mash them up in a mortar and pestle or a blender. Add them to the sauce.
You'll have a great curry nine times out of ten. Some things like corriander seeds are mild so you can go hard, but we all know that chili burns twice if you go overboard.
Thai/Malay/Indo go for the same basic ingredients as Indian but with a "Sweet/Sour/Spicey/Salty" blend. Use tamarind, palm sugar, fish or oyster sauce and Chili - often with coconut cream. Steer clear of the dominant Indian spices like cumin for East Asian curries.
The fun part is mixing it all yourself without a recipe. After a year you'll have your own great recipes and absolutely no internal parasites!
