I love this string Chrsitmas from Trocas de Linhas (you are going to need Google Translate for this one):
It reminded me of these yarn candy corns:
And you could make a bunch of them without having to buy a ton of Styrofoam cones. Mariangela uses one cone and covers it in plastic wrap to make the trees. Then once the glue dries she can easily remove it from the cone.
She uses white glue, but I bet mod podge would work too! So many options!