If there was ever a Mesoamerican civilization that has been subjected to fluffy New Age revisionism, it's the Toltecs. Perhaps the most infamous contemporary author guilty of that is "Don" Miguel Ruiz, author of The Four Agreements and founder of The Sixth Sun foundation. Imagine their surprise to learn that the Toltecs, like many other Mesoamerican and South American civilizations, engaged in child sacrifice.
The Toltecs occupied the central valley of Mexico between the 10th and 12th centuries, preceding the Aztec civilization. This find by archaeologist Luis Gamboa is forcing many people to re-examine their beliefs about the highly refined Toltec civilization.
The sacrifice of children, both by the Aztec and now the Toltec, was reserved for the most serious of acts, the appeasement of the rain god Tlaloc. Read the National Geographic story about this precedent-setting find.
The Component of Sacrifice in Aztec Reconstructionism
It goes without saying that any contemporary effort to reconstruct the Aztec religion must include a component of sacrifice, albeit not human sacrifice (due to obvious legal constraints). In my personal practice, I reject animal sacrifice as well. What I do believe is essential, however, is that if you wish to honor an Aztec deity, then you must give of your own blood. How you choose to do that is certainly open to interpretation, but the use of an obsidian blade or a maguey thorn would be traditional.