For this DIY you are going to need:
1. A bunch of pinecones
2. Some thread of your choice
4. Hot glue - optional
I didn't take specific measurement for this project. Lay down your thread and place the pine cones at the same distance, more or less. Now cut the thread and start to tie it around the bottom of your pine cone. I've bought this ones that have a little pinch on the bottom, and it's easier to create a knot around them. If you don't, just use regular hot glue! It literally takes 10 minutes and the result it's really pretty and Autumnal!
I also want to link you to this lovely video, that shows you other lovely ways for creating Christmas pine cones ornaments and decorations!