So when I look for FC's, I like to get a feel of how I picture my character. And this varies based on the RP. I'll usually scour FC tumblr pages, as mentioned, but I will also look for TV shows, movies, etc. that heavily feature the setting I will be RPing in. For example, if I am joining a Victorian period RP, I will be looking at shows and such that revolve around that setting. Google image results help a lot.

I also look in my free time. If I see someone I think will make a good FC down the road, I save it in a PM to myself on here (and a back-up, just in case). I have about 15 at the moment, for various settings.

As I've grown as an RPer, I've decided I don't like art as my FC. I prefer real people, but that's personal preference. If you use art, I feel you need to give the artist credit for their work. It's different with a celebrity since they can be easily found (though I will, of course, tell ppl who my FC is if asked).

Either way, I would just google dive whenever I have free time. It can be a lot of fun!