I created the designs in Adobe Illustrator and printed out the patterns to use as templates for cutting the glass and laying out the pieces. Then the glass pieces are placed at the bottom of the mold, upside down, and concrete is poured over the top of the glass pieces.
I don’t actually “step” on these.
I’ve created some with smaller glass pieces that I’ve put in traffic areas that get stepped on. The glass pieces in these are larger and I’m afraid they will crack if they get a lot of traffic.