>>34937851as long is it's not too similar the background shouldn't matter. I had similar issues with background when I tried it with textual inversion but dreambooth worked much better with the same images.
I have had better results when using a token that is already close to what I wanted. Don't use "sks <class>" that some tutorials recommend. For example for this one I used "succubus girl" for dreambooth token and "girl" as prior preservation class. I used 1000 class images for prior preservation generated automatically with just a prompt "girl".
