Toasting spices revives them. When in doubt, give all your spices a light toasting before using them. Some recipes require a deeper toasting, actually roasting the spices until they darken considerably—Thai curry paste falls into that category. When several spices are used in one recipe, I recommend the spices be toasted separately. The different density, moisture content, and shape are all factors that determine the length of time it takes to roast a spice. Begin separately, then intuitively you will begin to learn that some spices can be toasted together. When toasting cassia and star anise for five-spice powder, I toast them in one pan.