Some of you have been asking me about my lighting technique to get black background photos. Since it seems impossible for me to answer your questions without photos, I thought I would write about it here.
If I am photographing one object, I often do it on my dining room table, in the morning. I have a big glass door in there so the light just pours in. It is east facing, so in the mornings, there is strong light (eastern and northern light are the best for photography - not as overly strong as west and south can be). My dining room furniture is rather dark.
You can see in this picture that I have exposed for the whole room. Because the lighting is so streaky, anything in the room that is in that strong light is over-exposed. The exposure is made for the darker parts of the room. If I wanted to get a properly exposed photo of my overall dining room, I would not take it this time of the day. Notice the bowl on the table. You can see that it is overexposed in that light (click on the photo to make it larger). If you look at the rim and what you can see of the part of the bowl that is in the light, it looks almost white with this exposure. I can use this light to my advantage to photograph single objects like this.
When I want to get a photo like this, I get in close and expose for the object. This works in the opposite way of the first photo. By exposing for the bowl instead of the dark objects, the bowl is properly exposed and everything else is underexposed. Everything that is underexposed goes black. I use a wide aperture. In this case, f/2.8.
Now I know you may not have a set up just like this but I bet you will be able to find one. Look at the light that comes through the windows in your home. Our eyes don't really see things like this but our cameras do. Look at different times of the day. It will change during the day and also as the seasons change. My "dining room studio" works best during the spring and fall.
Hope this helps and you can find your spot! I'd be happy to answer any questions you may have.