You can easily prepare and carry multiple tacos at once by using a muffin tin or an egg carton as your prop.
I'm not sure who is the source behind the photo above, but it was shared on Pinterest by Koh Tao Playskool. There's another photo on Pinterest showing the muffin tin version — turn the tin upside down and use the spaces between the cups to hold the taco shells upright.
You can also line either with plastic wrap for easier cleanup.
[via Cook's Illustrated]