I start with a wood panel and use tape around the edges, to keep the wax from spilling off the edge. 
Using a potholder to pick up the edge of the wax container, I pour the wax on the panel.
It takes almost no time to cool and harden, so I work quickly pouring colors while the others are still hot, so they can mix.
After the last pour, I wait at least 20 minutes before taking the tape off the edges. You can tell a lot of wax was built up during this process.