If the rub you’re making has whole spices, it’s always a good idea to lightly toast them in a dry skillet for a few minutes to bring out the flavors. Just toast them until they are fragrant.
Add whole spices to a grinder. Pulse them until roughly ground. You don’t want them like a dust.
Mix in other spices.
If you’re using rubs on meats, coat liberally. Go lighter on veggies or tofu.