I did so much research and finally decided that a raw meat diet was the best choice, both for my dog's health and my wallet. I use (loosely) the Prey Model Raw diet and have seen amazing results. To get the best prices on meat, you have to have a place to store meat bought in bulk (like a chest freezer), but I found mine on Craigslist for $20. Please let me know if this is something you're interested in, because I know of a lot of helpful resources. Raw feeding is growing in popularity because of its amazing health benefits, and there are so many forums and sites for advise.

If this isn't a route you want to follow, at least visit Dog Food Advisor to compare dog food brands. You would be shocked at the terrible ingredients dog food manufacturers are allowed to use. Dr Karen Becker also does a couple really good videos on choosing a commercial dog food: link

I'm realizing after writing all this that you may not actually be looking for advise. But here's my answer anyway

I go by what the dogs will actually eat and doesn't make them sick.

Try and do some research and some pricing

Not gonna lie, I just go by price.

We just use what our breeder recommended.

I go with my vet's advice, and then through trial and error, because not all prescription foods work with my dog's sensitive stomach.

After working at a retail pet store for almost two years, I did all of the research I could about every food and came to a decision myself. I feed my dogs nothing but natural, organic ingredients in a dog food. They love the taste and would never go back to any kind of other processed food again. (Literally! I tried to see if they would eat the stuff I previously gave them, which was not all that bad, and they wouldn't touch it. They were grumpy until I gave them the new food!)

I go by price and what they like

*cat for me haha, I don't have a dog!

I usually at least read the ingredients to make sure there's MOSTLY meat in it, I won't feed her food that's mostly soy/corn/grain. There's a few brands I trust and frequently get, if I can't get one of those I just find a mostly-meat natural or organic brand.

We went by our vet's recommendation

I have cats, not dogs, but kind of the same thing. I read labels just like I do for human food. Turns out that Costco (yes, Costco) makes a fairly decent cat food. Chicken meat is the first ingredient, and there are no by-products or allergens like corn or soy. In an ideal world, there would be no grains at all for cats, but I'd much rather give them something with rice than corn, soy, or wheat for that matter. It is only about $18 for a 25 lb bag, so very affordable.

P.S. I wanted to add that it isn't good to keep changing a cat or dog's food, as their digestive systems are very sensitive and they can get sick. Whenever you change brands, be sure to SLOWLY mix the new into the old, not just change it cold turkey.

We feed our animals Blue Buffalo. It's pretty pricey but worth it! Our cat eats the wilderness type which is high protein and grain free. We wanted something where MEAT was the first ingredient. We just got a new kitten and her previous food was the cheap friskies kind so we're now working on slowly switching her over.

My dog has to have prescription food, so I buy it at the vet's office. I just buy what the vet tells me to.