I'm personally a stickler for reference. Everything I do, I'm always looking at photos at the very least, to help get a better feeling for what I'm painting. It's best if I can examine whatever it is in reality, but working with fantasy and science fiction subjects, that's not always possible. I have to sort of cobble together what I have in mind.
If I'm working on creating some sort of creature or beast, I'm looking at animals. Fur textures, skin textures, you name it! What's more, I'm looking at animals that are similar to what I want to design -- if it's a dragon, say, I'm looking at all sorts of scales, shots of reptile and avian skin -- sometimes even fish! If I'm designing an alien, even more fun, because then, I'm all over the place -- I want something that's believable, but also "alien."
If you don't use reference, or think that it is somehow cheating, ask yourself why? How are you supposed to know what it is that you're painting or illustrating unless you know what it looks like -- even if you're not looking at right when you're doing your initial work, if realism and representational work is important to you, then you want to see what it is that you're working from.
In the long run, the real art comes from not how well you copied the texture of something, but how well you've created a mood, and a feeling through taking what you're working with and putting it in another situation. Good reference is rarely directly copied, but always used as a strong influence.
Google images is a great resource for finding photographic reference. I'm using it constantly. Since I'm not copying the photos, there's no copyright infringement -- I just need to know what something looks like. Along the same lines, Corbis.com is also a great resource for image reference, and one I've used for years. I'm sure other image sites like tublr or photobucket can provide great resources as well.
This is what a typical reference sheet looks like for me:
|Typical reference page for a painting|
If you're interested in doing representational art (even if you're not, it's good to practice), using reference is an incredible boon, and in no way "cheating." Your art will be stronger for it in the long run.
Since this blog post was made, the piece that I was working on has been released:
|Copyright Wizards of the Coast|