When my sons were young I would ask them to pose for me. At first they were very happy to do so. They were too young to sit still for very long at that time so I don't have any finished sketches from those early sittings. Later, they would finally submit, but as you can see from the two top sketches, they didn't have to like it.
These usually only took about 30 minutes, but felt like an eternity to them. I really wanted to draw from life instead of photos, so I would beg, conjole, bribe whatever it took to get them to sit for me. I would draw what was there. I have lots of pouty sons scattered in many sketchbooks.
Below the two grouchy sons is my eldest son. This one is unique because, of my three sons, he most disliked dressing-up and posing. He never got into the theatrical aspects of it all. He was a baseball player and a scholarly sort. But I caught him in a good mood one day and he dressed up for some studies of "Rip Van Winkle". Here he is as Rip doing what Rip did best - daydreaming.
I also took some photographs of him in the get-up to use for reference later. He took it all in stride, but asked me not to show them to his friends. I believe this was his first year of high school. I kept my promise and did not show them to his friends. I don't think he'll mind if I share them now.
Now everyone is too busy to pose. I've resorted to occasionally setting-up photo shoots with as many of them as I can get in costume. I now try to get the wife and girlfriends involved. I have a really great idea currently brewing in my head that I want to get reference photos for soon.
One day I'll get all the paintings finished that I've taken these photos/sketches for. It is always good to have a large reference library of photos you've taken yourself. If there is time while you're doing the shoot, sketch out a few ideas and file those away. They will come in handy at some point. And even grumpy subjects are good for sketching.
Get out a sketch something. Paint something. Just Draw! I'm headed to my canvas now.