Dogs tend to be a bit easier to pose than cats, as it doesn't take as much to get them interested. A quick whistle, a cry of 'where's the cat' or any funny noise will usually get their attention. All animals have their own individual characters, but it's fair to say that cats are usually less eager to please. Patience is key, and you may need to wait a while for the cat to relax. Try getting them settled in one position, such as a comfy chair or a stool (you could even bring their pet bed). Keep a favourite toy or food bowl to hand, and gently tap it above the lens to grab the cat's attention. If they won't do what you want then be prepared to change your approach – after all, if being aloof is part of their character then why not capture this in the photograph?