sorry to hear about the dog. These are not too bad but I would take a whole collection of photos of the dog in different places and times of day, awake and sleeping etc and try to photograph his collar, tag and toys and feed bowl. Print them out then cut them into different shapes and sizes
along with some photos of him as a puppy or younger. Get a large frame and put them all in randomly untill the space is filled. It will make a great memorial of a loved pet.