Shaping and cutting out panels, assembling them, and finally settling finishing details of the project are basic steps in building a dog house. With four walls, a base, and a roof, dog houses are fairly easy builds but you are only limited by your imagination when it comes to what you think is the best for your dog.
As with all concerns with your dog, safety is always a priority. This applies not only to the design and structural integrity of the dog house such as an elevated base to prevent water from entering it from the ground. You should also take note of details such as the type of material you're going to use for the build by putting a premium on plywood treated with nontoxic preservatives.
Aside from safety, only you could anticipate your dog's particular needs to deliver the most comfort with your design. A dog house, after all, is a reflection of how much you know and care for your dog.