Picturing glass was one of my first works in studio, actually it's not so hard if you have glass only on tabletop but if you have something from steel or some other material it can be difficult. There are two types of picturing glass. One is as I call it "through the glass" and the other is on the glass. What that means? First "through the glass" means that you will light your object through it, for example put your glass at the glass surface. Than put white paper as a background but spread it also on the floor like letter "L" but with rounded angle not acute. Ok, also you can put some mat white 80% transparent paper below glass you're shooting at. That paper will erase all ugly reflections at your picture. Also put 80% transparent paper around your glass as in a cube.It will erase all reflections from your room. Ok now you did 90%. Your glass is in white paper cube standing on glass surface with one paper below it but at a little distance few inches 5-10 it depends. If you put your paper closer to lightning object (reflector) you would get more direct light and if you put it far it would be soft.
Here are some tips. If you want to see more shape of glass you can use dark or black paper and put it vertical on both sides of glass and one at the top of course at some distance it depends of how glass is thin.
I took some pictures of it at similar way and it looks like this
And there is other way of lightning glass when you light it with soft light, it would be the best if it is from big source not point cause it will look bad as a reflection. When you are doing that try not to lose glass material. The meaning of "glass photography" is to see it is a glass, not plastic or some other material. So U can put your light source wherever you want. Unfortunately I don't have example for this type of light but I have some steel life photo I took with reflectors imitating outdoor light through the window.