All the stills and most clips I use are public domain from wikicommons or pixabay. You can also get stills that are royalty free which just means you pay a one time fee from just about anywhere. Just search for royalty free images. For the film clips that are in Girl It's Gone, I contacted the filmmaker and have his written permission. Years ago on that one I had a copyright notice over the clips but it wasn't from the original filmmaker - it was somebody else who used his work in their video. So I disputed the claim and since I had his written permission I won.