This is a project I love to do with beginners and children. You can use any opacity of glass that you want, but I love doing these with some clear because it give a really fun "magnified" look.
1. Cut a 6x6" sheet of glass into 1/2" strips.
2. Cut a 6x6" base in your choice of color.
3. Place six half inch strips going one way. (I glue this layer because otherwise it's like playing "Jenga" when you place the top layer.) Hint: Use a strip to measure the space between stripes.
4. Place the other six half inch strips going the other way.
5. Full fuse (I did between a tack and full fuse on this one and got a little more of a spreading than I wanted.)