Sure, you can find many dog treat recipes, in books and online, but making your own doggie snacks allows you to get creative, it also allows you to add or delete ingredients to suit your dogs taste, or special diet requirements.
Some dogs "not mine" are actually very finicky when it comes to eating. My mom's dog Barron is very picky when it comes to what he will and will not eat. This is great for me, as Mary gets all of the treats that her dog won't touch. She spends large amounts of time, effort, and money finding Barron just the right snacks and when she has found the perfect one, he gets bored of it and turns up his nose. I don't actually believe in giving a dog that much power, but Barron is her baby and I think pleasing him makes her happy, so live and let live.
Guess what, dog snack recipes are pretty simple, anyone can take a basic treat recipe and change it to suit their dogs taste. Take your basic peanut butter dog biscuit recipe then add cheese. You may be saying peanut butter and cheese (yuk) but the truth is dogs actually seem love some combinations you would never think of eating yourself.
How about making dog biscuits to solve a problem. Lets say, even though your dog has good dental hygiene. He or she is normal, happy and healthy, but always seems to have foul breath; try adding a little mint or parsley to your dog biscuits. Fenugreek seeds have been proven to reduce bad breath, try adding a few of these seeds to your dog treats or food.