These are just VRay Mtl materials slapped onto two glass models in Autodesk Maya (shouldn't matter which software you use though as these are VRay specific). I changed the transparency to full and the amount too. The glossiness is on 1 (which means clean glass), Refraction IOR is 1.6 for the glass as it is standard for glass surfaces. On the glass to the left I added a slight blue Fog Color. The one to the right has completely white color. I get a few problem areas mainly at the top and at the sides of the glass.
I'm gonna play around with the Fresnel a little (now currently locked to the Refraction IOR). The very tip of the glasses gets really black, could be because of the background but I better check my settings and the amount of Refraction and Reflection subdivs (currently 10 which should be more than I need actually, 4 or 5 would suffice I believe at the current setup.)
I have a very simple rectangular light just above. No settings changed there. I will prob later.