if your going for more than 1 day...
PJ's
toothbrush
tube of toothpaste
deodorant
hair
brush (if you use one)
cell phone
phone charger
shampoo
conditioner
fun stuff to do in the car or plane and at the hotel at night
if your going to a pool bring a swimming suit
You weren't very spacific on if it was vacation or a buissness trip or just a one day thing so that is the list i use.