Look for pieces that will stack well together and have a flat gluing surface on the bottoms. This will help prevent water and air from getting inside once they are glued together and it will help the totems look level when you have a flat gluing surface to work with.  A plate between each piece adds to the overall look as well as helping the pieces be sturdier once glued together.

Step 2:  Preparing the Glass
Lightly sand the surfaces that will be glued with fine grit sandpaper (diamond dust paper if you can find it).  Clean all glass well with warm soapy water and make sure they are thoroughly dry and lint free before gluing.

Step 3:  Gluing
Use a clear silicone glue for best results. Make sure the adhesive you use is weather resistant. GOOP brand marine glue works well.  Glue pieces in sections, letting each section cure before putting them all together as one piece. Try gluing the pieces during low humidity to reduce condensation.  Leave small air holes in the glue seal where there is an enclosed air space to allow for temperature expansion and contraction.

Step 4:  Displaying Glass Totems
You can make free standing totems or use an upside down vase glued to the bottom to mount them on poles. Copper is a popular choice.  You can also use PVC conduit pipe (the gray stuff in the home improvement stores).   Paint it using a spray paint specifically for plastics to give it the look of copper or any other color you may like.  Rebar is pounded into the ground first and then the conduit is placed over that. 

Glass totems really sparkle in the sun and look great in the garden. The options are endless.