Meltzer takes thin black paper strips and tapes them to the inside of the light tent so that they line up perfectly at the edges of the object thus defining the objects corners in a 'natural' manner for the shot. Sometimes when using a tent and a white card on the front of the camera you will see the camera lens itself as a round or oval black reflection in the object. In that case slowly raise the camera on its central cranking column. Look through the lens as you do this and at a certain point the black reflection will slide out of view. At that point tighten the camera into position and take the shot.
Copy stands Copy stands also provide a way of dealing with reflective objects.
For flatter items, coins and much jewelry a copy stand is a good solution as a photo - booth system. As described before there are horizontal and vertical systems. What follows deals with a vertical system. You can mount the camera looking straight down and create a bag around the object suspended from the camera itself so that the entire interior space is within a tent. I would have the lights fairly close in, but I no longer recommend this approach with a pillow case, because regular cloth is laundered, and commercial laundry soaps have what's called bluing in them.