all of the above except usually yandex instead of google
Yeah, all of the above. A "trick" of mine is just searching for a descriptive filename on the archives because it's usually the case that someone will have saved an image and given it a name.
If I have the patience or care to do so I just ask someone on /wsr/ if they have it.
Works well most of the time if you can be descriptive.
If I had a lot of images and was actually good at programming, I'd set up a way to search by color.
I think yandex is a superior image search engine, because it looks for pictures rather than ads for things it tries to sell you.