I'm experimenting with pattern creation so my first pattern is relatively simple. I decided to do Stephanie's dress from LazyTown since it's a simple stripe pattern. I think I've got the hang of it though.
I'm wondering if for the more complex patterns if fabric swatch or wallpaper sites might make good basics for pattern making? I know I really want to try and find something that will work for Princess Fiona from Shrek and I also want to make some Sims based on Rock of Ages and Power Rangers (all seasons).
Just make sure what you use is copyright free Unfortunately I have a friend who's studying intellectual property in law school atm, so he's made me very sensitive about that, lol. Though one thing he told me that I wouldn't have guessed is that if you're making a pattern based on a photo on a website, the copyright holder for the image is actually the photographer, unless they were paid to take the picture or otherwise transferred the copyright to the designer or somebody else.
If you find something that is clearly copyrighted, you can always ask permission to use it. If you acknowledge the designer in your upload, it's good advertising for them, so they're likely to say "yes".
Anyway, there are several sites which have great materials which are fully tiling and explicitly free to use. One that I found the link to around here somewhere, that might be useful for your princess dress, is http://theinspirationgallery.com/ .