How can i get a proper reflection on a material without a background or another objects? i'm trying to make a shining/reflection material but i don't need to add any other object to the scene/layer, is there any way in order to do this? or should i add objects and then just hide them from the render?

Reference (as you can see, there are lights/reflections but not other objects)



Or, more realistic 'metal' like this?
In Cycle render engine you have an option to disable direct visibility of the objects to the camera. 

Open Object Data tab and in Ray Visiility section disable this option on all the objects that you want to be invisible in render.



You can do the same with the background in World tab.