This is a short test that I made to try and get glass to look right, the only problem that I have run into is that the inside of the glass appears to be a gray/silver, and in the rendered animation the when the camera circles the glass and the cube is behind the class the cube is not seen through the glass as it should be.
Any comments or suggestions?
glass.blend (145 KB)
You should really ask this sort of question in the support forum as it will be read by more people.
The ior was a little high; 1.5 is normally about right for glass and I turned down the mirroring a bit. Its also good to enable TraShadow on the objects that receive the shadows when you have transparent objects in a scene. Otherwise the transparent object will cast a deep shadow that looks as if light isn’t passing through it.
Here is a quick render:-
…and here is the .blend:-
glass.blend (38.6 KB)
Good luck!
Thank You Very Much, This has helped immensely 
I tried to render your scene and couldn’t believe why it was taking so long, granted I don’t have the most powerful computer but than I started looking around. you have your osa turned on way to high you don’t have to use 16 samples unless its needed, you objects each had two subsurf modifers acting on them set, one of the modifers had its viewport level set to 6 and its render level set to 2. this made the 3d viewport slow to work with,
coming to the materials themselves ref and spec values are all wrong, the basic material rule is that both these number should not add up to more than 1. the more reflective a material is the less of its own colour it reflect back so you should lower the diffuse reflect value and rise the spec and mirrorr value. they should sum up to one.
don’t use blue as the base diffuse colour for your glass it should be a grey, this is one of the more common mistakes people make when creating glass shaders.
when setting the ray depth that you need count the number of refractive surface that a light beam would have to cross through you glass object to get to the other side and set it to that setting it higher just increases your rendering time in your scene I counted 4 such surfaces, you had it set to 10
the last point is that in order for glass to look right it needs something to reflect either place it in a highly modeled enviroment or use an hdri image to give it something to reflect or it just won’t look right.
p.s. run a search for ‘photorealistic texturing Leigh Van der Byl’ she has one of the best introductory texturing tutorials I have read and will give you some useful tips in making better materials and textures.
