When large dogs eliminate, they eliminate a lot more than small dogs. More goes in and more comes out of large breeds. Which is something to keep in mind if your dog will live inside - especially if you live in a high rise apartment and he will have to be litter box trained (there is always going to be more to clean up).
Trust us, not all mixed breed dogs look like junkyard mutts (which come on, are pretty cute too). In fact, here is a rule of thumb: when one gorgeous dog breed mates with another gorgeous dog breed, the end results are -- wait for it -- pretty darn gorgeous. That is science, baby! Here are a number of wonderful examples of some of the most adorable mutts out there.
So keep in mind that if you choose a breed with a long coat you will either need to get it clipped regularly if you want to avoid brushing it so much, or if you choose to keep it long or even medium length you will have to brush it every day.
Your dogs temperament should match yours. Do not choose a breed that is highly energetic if you are a couch potato. On the other hand, if you want a dog that will follow you everywhere around the house and who is always ready for a game of fetch or tug of war then you should consider a dog that is highly active and always has a lot of energy, instead of one of the lethargic breeds.