Materials:
New or old terra-cotta flowerpot
Mosaic glass glue
Black mosaic glass grout (available from craft shops, home-improvement centers and glass retailers; do not use tile grout)
Mosaic grout sealer
Assortment of colorful art glass
Stick & StayŽ adhesive
Mosaic glass cutter
Glass-breaking pliers
Safety glasses
Rubber gloves
Paintbrushes
Masking tape
Paper cup for mixing grout
Abrasive buffing pad
Wear safety glasses and rubber gloves. Cut small pieces of glass, using a mosaic cutter or a standard glass cutter. Use the mosaic cutter to score the glass on the shiny side, then grasp the glass with glass-breaking pliers, with the edge along the score line, and snap the glass to break it at the score line. Or place the glass in a plastic bag and hammer it gently to break it into unevenly shaped pieces

Mosaic glass pieces will be applied only to the rim of the terra-cotta flowerpot, so mask off the rest of the pot by running a piece of masking tape around it just under the rim. With a paintbrush apply mosaic glass glue to the rim one small section at a time, and arrange glass pieces about 1/8" apart on the adhesive. You may also transfer a design to the flowerpot with carbon paper

Mix grout in a paper cup, following the instructions on the package.
Use a small brush to apply the grout to the mosaic tiles on the pot. Be sure to get grout between all the glass pieces. Let the grout dry 10 to 15 minutes. It may be dried with a hair dryer, but if it dries naturally, it's less likely to crack

Use an abrasive buffing pad (not a household scrubbing pad) that contains a special abrasive material to remove dried grout from the glass

After the grout has dried, apply mosaic sealer.
Variations
Add glass mosaics to ceramic tiles.
Use glass mosaics on a piece of glass to create a house-number plaque to distinguish your house