I have tried so many different variations of this recipe over the years. I was trying to find one that tastes like the ones you buy already mixed in the packet at the store. So many times I have been disappointed. There were some good ones though, like Alton's Taco Potion #19. But it just was not what I personally was looking for. This recipe below is what I believe is the closest thing to the packets I am used to.
It is so economical to make it yourself. I have not done the math yet, but the cost is bound to be cheaper. My mother's dollar stores carry all of these ingredients. So seven dollars for seven ingredients equals seven packets of the store bought stuff. Or make it yourself and get way more than seven packets.
1 Tablespoon minced dried onion
2 teaspoon chili powder
1 teaspoon salt
1 teaspoon garlic powder
1 teaspoon corn starch
1 teaspoon cumin
1 teaspoon paprika
1/2 teaspoon cayenne pepper
Get out 10 little snack sized baggies.
Add each ingredient above one at a time to each bag.
Store for later.
Note: I personally do not add water to the beef along with the spice. I think the beef releases enough juices to use and it makes a thicker coating. My kids hate runny taco meat!