They harvested cooled lava which became a volcanic glass, obsidian, then smashed it using a rock in pieces that would fit the type of tool they needed. This breaking was what created its sharp edges. From there they usually would take a wooden stick and carve out holes into it to hold the obsidian. Sometimes they would use rope to secure the pieces of obsidian onto the wood or with things like axes they would carve a hole through the stick to push it through. They would often crave designs into the wood for religious reasons as well or just for decoration. Rope would often be wound around the handle for comfort and stability. 

The Maya people commonly used these tools for their religious rituals so they needed them to communicate with their gods. Not only this but it was a piece of what gave mesoamerica value. They had more valuable things to trade which overall brought their value and strength up as a civilization. In their wars it provided one of their strongest weapons and an advantage to what they were able to do to their opponents that couldn't. Especially considering that obsidian was more common in their area which made those tools easier for them to use. Obsidian tools were used during many stone ages, wars, and metalworking cultures.