I used popcorn seeds for the base and added a pine cone, silk leaves, some plastic gourds pumpkins and berries, ornamental gourds, and a caramel scented candle.
Lately, I have been adding something scented into most of my sensory bins as it involves another sense and I find my kids really enjoy it. I am careful not to add anything that smells too intensely so as not to overwhelm them. In this case, the candle worked really well as the kids enjoyed filling the top of it with the popcorn and dumping it out. The bumpiest of the ornamental gourds was the favourite item in this year’s Thanksgiving sensory bin.
If you are looking for information on making sensory bins, you may be interested in my book. 
My son with sensory processing issues will love this activity! Featuring at Family Fun Friday in my round up of 15 FREE and Easy Thanksgiving Activities for Kids: https://www.happyandblessedhome.com/15-easy-thanksgiving-kids-activities/ Happy Holidays!