For children it's huge fun getting dressed up like a pirate, a cowboy or a witch. You can start photographing when you are going shopping and the little ones pick out their Halloween costume.
Take photos of how your children get their make up. You could take Before and After photos. Then place them miced up on a double spread of your photo book and play memory with the small ones. Find the masked and the unmasked child.
Of course the highlight of every Halloween is, to go through the neighbourhood streets and knock on the doors with the sentence „Trick or Treet!“ Keep your camera ready when the kids get their sweets and how their smiles and eyes get bigger and bigger, with every chocolate bar more in their bags.
Normally all this happens in the evening and everyone knows, how difficult it can be, getting a non-blurry photo when it's dark outside. You should dispense using flash light, because faces appear white and the spookyness is gone, too. Try to use a faster shutter speed. You could use a tripod as well. When the camera stands still, the chance getting a blurry photo again, will be very small.
Document how you decorate everything and getting dressed for the party. Take photos of everyone present. Of course everyone has to come in a halloween costume. And you will laugh at the funny costumes everytime you look at those photos. Have a spooktastic time!