dark grey is usually what I use if the item is too light to use on white. I'm not opposed to using black though. As long as your pictures are sharp, I think you should use whatever colour makes your item 'pop' the most. Just my opinion though. I'm not really into stark white everywhere. I always make sure my backgrounds are neutral coloured, plain, and I always use the macro settings on my camera.
By the way, your Halloween candles are really cute! ♥