Lately I've been making a few trees for my Oregon Coast route. I've also been pushing myself to make a few that are not of the usual shapes I've made in the past. It's after Christmas now, so pardon me if I immediately divert from trees that look like isosceles triangles.
In fact, I would even go so far as to say, having spent some time about the woods here in the Pacific Northwest, most trees, in a forest setting, do not have the upright triangle shape. I'd say they're more like inversed, or upside down. Trees are (often) wider at the top, where the most active foliage is busy catching the sun's rays. Under this canopy, you'll find shorter, thinner, and less viable material. Please note, this pertains to a forest of trees. With all due respect, solo trees out in open areas tend to retain the isosceles presentation.
Try packing "traditional" tree shapes close together. It's not easy to do unless you leave plenty of (vertical) room between the foliage pieces, so you can wedge them together. (Forests' know; they don't even try). I'll post a photo of my current project, as soon as I have more than a few posing for a shot. I'm already wondering if this could be / should be a new product idea?