Buy whole spices, not ground. Get:
Cinnamon stick (not the Mexican kind)
Cardamom, preferably both green and black
Red chilis, or red chili powder
Wet ginger paste (go to an Indian grocer’s), or fresh ginger, never ever ever powdered ginger
Garam masala, here a good powder from an Indian mart is OK though better to make it fresh
Turmeric, powder will do
For bases, draw upon:
1. Sauteed and pureed yellow onions
2. Plain yogurt, some will wish to add heavy cream as a thickener
3. Coconut milk
Now start your dish. Create the chosen base. Ghee (clarified butter) can be added to #1 or #2 for yummy richness but I usually don’t for health reasons. Don’t mix #2 and #3.
Then take your preferred mix of spices. Fry the hard ones for two to three minutes over medium heat (3.5 on an electric stove) and puree them. Cinnamon stick should be left whole in the sauce to leach out its flavor. Never are more than three cloves needed and they can be left whole too. Cardamoms can be inserted whole and then removed, especially if large ones are smashed open a bit with a blunt edge. Otherwise experiment with preferred combinations.
In a separate pan, quickly cook your preferred meat over high heat, just enough to make it a bit translucent or pink. Insert the partially cooked stuff into the liquid base and turn to low heat until the dish is ready.
Vegetables can be substituted for meat.
You can introduce mace and mustard seeds, or tomato can be a base in sauces.
You now have a combinatorial knowledge of many many Indian recipes and you need not memorize anything.
By the way, if you must buy powdered curry, Golden Bell is by far the best. It is packed with bay leaves and stays potent for months. You can sautee some chopped yellow onions, toss in ground lamb, douse it in Golden Bell, cook over low heat until dry, and when on the plate, over rice, coat it in plain yogurt.