One can make one's own decorative bottle for storing holy water. Get a nicely-shaped bottle --preferably one with a flat surface on one side -- with a gold-colored or silver-colored screw on top, such as the bottles below:
 

 
Soak the bottle in hot water with a little alcohol to totally remove all paper and sticky glue, and let it dry thoroughly. Make a stencil of the words "Holy Water" ("Aqua Benedicta" in Latin), or a stencil of an appropriate symbol, such as the fish, or a symbol of Baptism. Use a chemical etching agent to etch the glass with the words of symbols you've chosen.
 
Chemical etching agents can be found in craft stores such as Hobby Lobby or Michael's. Follow carefully the instructions that come with your etching agent!