!div style="display:none"!fjrigjwwe9r2content:tip!/div!!div style="display:none"!edf40wrjww2content:tip!/div!1. Glass has no real identity of its own. A glass against a white or black background cannot be seen very well. Glass takes its shape from the reflection and interaction with other shapes around it. You need to place your glass so it distorts something behind it or reflects light and image from objects near it into the camera. Camera and item placement is key.
2. Modify the glass texture to include a slight colour -- blue or red to enhance the shape -- so light that passes through the glass will define it with the colour.
3. Use a double thickness when lathing an object when creating your glass shape. That is to draw a thickness to the cross section of the glass (in strata or illustrator) before lathing - an inside and outside surface. Then choose "one-sided" to get the best reflections.
4. In some lower light situations, edit the texture to include a small amount of "glow factor" so the material has its own internal light.
5. Use boulean subtraction to create an internal shape that matches the curve of the inside of the glass exactly to use as the liquid inside the glass. With the thickness of the glass and the internal liquid it will add to the illustion of thickness of transparent material.
6. If you want complete reality, create actual light fixtures to illuminate the scene. Our eyes are not used to seeing a glass lighted without seeing the reflection of the light providing the illumination. Only in a photography studio do they take the time to be careful to make sure no lights are directly reflected into the camera.