I took a mosaics class last summer and made this seahorse mosaic.  I took the class to learn about making mosaics - I had never done this before and really didn't know what to do or how to start. Mosaics can be made with anything and mostly tiles are used, but this one was done with glass. 

I thought of an idea (seahorse), the instructor helped me sketch a rough pencil-outline of my idea onto a 16-inch square concrete tile.  i then set about selecting my glass.  I used an underwater photo I'd taken as a guide for selecting the colors.  Used an indoor-outdoor, clear-drying glue (Elmers, I think) to adhere the glass to the concrete form.  Used a rubber mallet to break glass into smaller pieces and tile nippers to nip glass edges into pleasing forms.  I just started filing in my outline.  I found that if I stepped away from the project from time to time I was able to get a better perspective.  When I was finally finished gluing, the instructor helped me to select a grout color (we chose a gray), apply and seal the grout to finalize the project.

I picked up an ornamental plate holder rack from the thrift store to hold the concrete tile and put it on the wall over my goldfish pond.

I can't wait to make another!  Please let me know if you have any questions and I'll do my best to answer them.