Buying: Buy spices in small quantities from a store that has a high turnover. Spices tend to lose their aroma quickly, especially ground spices, buying whole spices and grinding them as needed is preferable.
Storing: Spices should be kept in a cool in dry place, in an airtight container. Spices don't last very long 6 to 8 months maximum; they will lose their strength and could even develop off flavors.
A simple idea for storing spices is to keep them in alphabetical order in the cabinet or drawer or arrange them by ethnic group. Put a date on your spices so you know how old they are.
Using: Toast whole spices to intensify their flavors. Heat spices in a little oil before adding other ingredients to your pan. Add spices such as cinnamon and cardamom towards the end of the cooking process, these spices easily scorch and become bitter.