Look for the reflected environment
A polished object acts as a partial mirror. Before moving the object repeatedly, look at what it is reflecting: a bright opening, a stand, a coloured wall or the camera itself. Improving that reflected environment may solve the problem more directly than changing the object position.
Use the edge to explain the form
A narrow highlight can describe a curved surface, while a broader reflection can reveal a plane. Test the size and position of the reflected bright area until the object reads clearly. Keep an eye on the darkest edge so that the shape does not disappear into the backdrop.
Compare materials in one frame
When combining glass, metal and a matte surface, allow each material to behave differently. Making every surface equally bright can erase the contrast that makes the arrangement interesting. Use a simple composition to keep these differences visible without overwhelming the viewer with competing highlights.