Add scratches to glass...

Both small and large. Any ideas?

This can be done easily using either a bump or normal map. I’m sure there is a way to do it procedurally as well, but thats not my area of expertise

You need to run a greyscale texture of some sort into the roughness slot of the glass shader.

In this case I have stretched the noise texture and run it through a colour ramp node (the colours in the ramp are RGB 0.9 and 1.0)