Maybe it was a really unique, interesting or plain hard pose to find anywhere online or impossible to shoot a reference pose yourself without expensive tripod equipment. Maybe you live alone and getting friends/family just isn't feasible or practical.
Enter my ideal solution: A website that allowed you to pose a 3D model.
Sounds simple, but it doesn't exist (maybe the universe is trying to tell me to do something). Until then, here's a free solution!
Go to DAZ Studio's website. Download either the Mac or Windows version. Check out the store full of free models. Install any you fancy. I went ahead and got the Victoria, Michael, The Freak 4 Base, The Kids 4 Base and Millennium Baby 3.0 models, to cover the bases for most of my fantasy illustration needs (though there are a few more that look cool too).
After installation, go to the content tab on the left hand side of the screen and physically scroll the scroll bar back until you get to this screen:
Select "content" ->Figures -> content. You should see a couple of the models you downloaded:
At least, that's as far as I could tell. I don't know where the other models I downloaded are. But anyway! We march on. Double click on one of those models and you'll get this screen:
You'll get this ugly grey blob thing. It made me pretty annoyed until I realised I should click on the Pose/Animate tab at the very top of the menu:
After you do that, you'll get a decent looking model:
Awesome! Now we can start posing! Check out the menu on the right side called PowerPose. There's a bunch of green dots. I found that this is the easiest way to pose the model. If you're busy, posing away and suddenly the PowerPose model looses it's green dots:
Select anywhere on the big model, a yellow box should pop up. Your green dots should reappear and you can keep posing away. Trust me, it took me a few minutes to figure that out, and that made me mad too! I swear if I invent an online posing model, it'll be really easy and so much less hassle ;)
Well, I hope that helps out someone! It's the easiest (unfortunately), freest option I've managed to find so far.