Rebecca is a writer with an interest in pets and health. She takes care of her Mum's cattle dog cross, Ginger, and owns 4 cats. 
If you're easily swayed by the smallness and seeming innocence of the puppies in the pet shop window, here are some things to think about first!When choosing a new puppy, it's best to think of it as a new 'lifemate'. And in terms of the size he will grow into, rather than the size he is now!
It could be difficult on everyone to choose a puppy on the basis of it's present size and puppy-like characteristics, only to find it grow into a breed that is bigger than you wanted. Or, with characteristics that don't fit in with your household. You may live in an apartment, and the small and cute puppy in the window that you brought home may turn out to be a rather dominating and big dog.
Or, you may simply want a smaller, slower moving dog, perhaps like the Basset. Yet the dog you chose turns out to have a lot of extra energy, like a terrier. High energy dogs need a lot of exercise, or they burn off that energy in perhaps mischievous ways. These are all issues to take into consideration.
Ultimately, if you research the breeds you're interested in, you'll find a much better match for your individual situation.