You can purchase curry powder or make your own blend using spices such as coriander, turmeric, cumin, ginger, fennel, mustard, cardamom, cloves, nutmeg, pepper, fenugreek, cayenne, red chilies. If the spices are whole, first lightly toast them in a skillet, then cool and grind in a coffee or spice grinder. Combine the ground spices and store in an airtight container. Do small batches and experiment!