As I mentioned in the previous post about homemade burritos, I worked at a taco joint. I will share a trick of the trade on how to get the meat inside the hard shell.
Scoop some taco meat up on an icing spatula (a pie server also works well.)
Swipe the meat inside the shell all up one side. The purpose for this is so that you get meat in every bite instead of just at the bottom, and there is plenty of room for cheese and lettuce etc.