I do have a number of objectives when I take a multiple dog portrait especially when one dog is big and the other two are small like in this portrait. To create a well balanced portrait the large dog, like the senior dog here must be in middle and more importantly laying down so he does not tower over the other dogs. Secondly, they must be close together if at all possible. Too much space between them is distracting and in my opinion makes for a weak portrait.
Then the key for me is to concentrate on capturing their different personalities in a series of portraits while keeping a sharp eye on them and encouraging my wrangler helpers to adjust them according to my specific directions. As you can imagine it helps as a photographer to have patience while doing this and I am blessed to have an endless supply.