Mix together mayo, sour cream, and taco seasoning in a bowl. Remember how I said I usually double this mix? Much like coach Belichick and the injury report, I lied. I always double the amount of sour cream and mayo, and then usually use about a packet and a half of taco seasoning. (Really to taste, but remember the longer this sits, the more the spices will open up on the cream so do not over do it. ) You can also make your own taco seasoning by mixing together paprika, cumin, garlic powder, and onion powder if you happen to have all the above on hand.