Ah yes... the unco-operative toddler ("NO!!"). I often find the parents are anxious about how the youngster will act, or maybe have expectations of a particular kind of image in mind ("Please, Missy, leave the ribbons in your hair!!"). The more anxious they are to get the kid into the photos (with the ribbons!) the less co-operative the child becomes. I've found that telling parents that 2 sessions are possible (if the child is having one-of-those-days), at no extra cost, takes alot of pressure off. They relax and enjoy the session more. Either the child relaxes too, and becomes more involved; or they come back a week later and Mr. "NO!!!" is now Mr. Sunshine. Two short sessions can get alot more useful images then one that drags out with everyone getting more miserable.
I find most people haven't got specific ideas about poses. I'd rather deal with that than someone who wants me to make them look like Demi Moore!
Hope you and they are happy with the results.