There's really nothing quite like the aroma or flavor of freshly toasted and ground spices. While it is certainly easier just to pop a top and have ground Cumin at the ready, the difference in flavor between freshly toasted and ground and pre-ground spices is enough to warrant emptying out your spice cabinet and starting from scratch.
Anything that is available whole (Cumin, Corriander, Nutmeg, etc.) should replace their pre-ground equivalents. Nutmeg is the shiniest example. Once you smell and taste freshly ground Nutmeg you'll wonder how that innocuous brown powder earned the right to share names.
Most whole spices really benefit from a quick toasting to wake-up them up and add depth and nuance to what might be flat and boring flavors. To toast, simply add whatever spices you plan on using to a cold pan, crank the heat and toss until the spices release their oils (aromas and a little sound should accompany.) Let cool and it's time for grinding.
Finding the right tool for grinding can be a little overwhelming. While there are certainly myriad options, the key things to look for are: the ability to adjust your grind and ease of cleaning. Manual, electric, Molcajete, Mortar and Pestle. Each of these have pros and cons, and none are necessarily better or worse. Personally, I enjoy the RPMs of a coffee-style grinder. In fact, I use my grinder for both coffee and spices. But what about the residual flavors?
A simple and easy little trick.
Add about 1/4 cup of white rice, set your grinder to it's longest (finest) setting, and let her rip.
Dump the rice, wipe out the housing (use paper towels or a pastry brush,) remove the excess and you're ready to go.
Now what to use the toasted and ground spices for? Spice blends and mixes are absolutely better when done yourself. A perfect example is Chile powder. Most pre-made Chile powder is anything but flavorful. When you do it yourself, the options are limitless and the flavor is amazing.
(Recipe makes 1/4 cup)
4 Guajillo Chiles, stems and seeds removed
6 Chiles de Arbol, stems and seeds removed
2 tsp. Cumin Seed
5-6 Black Peppercorns
1 tsp. Mustard Seed
1 stick, Cinnamon
1/2 tsp. Garlic Powder
1 tsp. Brown Sugar
1/2 tsp. Pimenton
Toast the Chiles, Cumin, Mustard Seed and Peppercorns until aromatic. Let cool a minute.
Add to a spice grinder with the remaining ingredients and process until smooth.
Use Chile Powder in anything from momma's Chili to your favorite Mexican dish.