Put all of your ingredients into a small mixing bowl, or a small glass jar with an airtight lid.
In the mixing bowl, whisk the spices together with a fork until well blended. If you're using a glass jar, just add the spices to it, secure the lid on it, and shake it until the spices are nicely mixed.
Store the taco seasoning in an airtight container and, if you can, label it.
Optional step: I like to note the "best before" date on my jars with a small label. To be as accurate as possible, I look at the best before dates of the dried spices I've used and use that to gauge when the blend might be best until. Spices won't exactly spoil, but they'll lose quality and flavor after a certain point.