About 6.5 million companion animals go into animal shelters each year across the U.S., but only 3.2 million are adopted - fewer than half the dogs, cats and other pets are actually adopted.

But some photographers, like Milla Chappell of Real Happy Dogs are aiming to change that.

From pre-designed Cats and Dogs photo books to customized everyday photo books, shelters and rescue organizations are partnering with expert photographers to build relatable, heartwarming stories of the animals that end up in shelters - and they're increasing adoption rates exponentially.

Milla Chappell, a NYC-based professional photographer says, "I partner with local rescue groups and shelters to take positive images of homeless dogs to try to show people that they can relate to these dogs - that they could be part of their family. I really do believe in the power of seeing photos in print. Mixbook creates a beautiful product and a beautiful way to do that."

How to Take Great Pet Adoption Photos

Shelters are often underfunded, relying largely on donations and volunteers to house, feed and adopt out pets - and that's where pet portraits can make a huge difference. While many shelters do photograph their available pets, they're not necessarily professional-quality. If you're thinking about photographing pets for your local shelters to create Mixbooks or profile them online, use these tips to get the best possible shots.

1. Skip the flash. Animals' eyes reflect flash easily, so look for a spot with plenty of natural light. Make sure the light is behind you and shining on your subject.

2.Watch the background. You want all the focus on the pet, so take your photos in a distraction-free area. Avoid parking lots, places with cluttered desks or floors, and other busy-looking places. Try photographing against a solid-colored background (but if you can avoid white, do - it doesn't do much to warm up your photos).

3. Get on dog (or cat, or lizard... you get the idea) level. Kneel, sit or lie down to get your camera eye-to-eye with the pet so your photos have the right perspective. Fill the whole frame with the pet, too, to make sure he or she is the center of attention.

4. Get the pet to look right at the camera. It's heartwarming to see a pet's eyes looking right at the camera, and if you're photographing for a shelter, that's exactly what you're going for. Try showing the pet a treat and bringing it up to the camera before you take your shot. Be sure to part with the treat right away, though, or the pet will quickly lose interest.

5. Get to know the pets and capture their personalities. Cuddle bugs, playful pooches and sleepy cats each have distinct personalities, so take a variety of shots that capture those characteristics. Potential adopters want to see headshots and full-body photos, and when you can get pictures that showcase an animal's personality, people feel more like they can relate.

Pro tip: If you're getting action shots, make sure your camera is set to a high shutter speed or a pre-set "sports" mode. That way, the pet won't show up as a running blur.

Have You Used Mixbook to Help Shelter Animals or Homeless Pets?

We'd love to hear about how you've used Mixbook to create pet portfolios and other items, so please share your story in the comments below to inspire others to do the same!