Hi. Photographers have a simple trick for photographing reflective objects. Set up a black screen with a small hole to poke the camera lens through in front of the object. Position the lights at a 45 degree angle to the right and the left of the object so they are not reflected, and the item is evenly lit with no glare spots. This way all that is reflected is a black void. Black cotton velvet works great, but black foam-core would also work.
If you need to diffuse the light for a household, incandescent bulb, I’ve found a piece of parchment paper (the type used for baking) held in place with WOODEN clothes pin (won’t melt like plastic) clipped to the front of the lamp is a cheap, low-tech system. The parchment paper should not touch the bulb, of course! If using fluorescent bulbs or LEDs there is little heat so you can use plain old paper or sheer cloth as a diffuser. Hope this helps.