I've noticed a fair amount of threads for deciduous trees but not much for pine trees. Over the Christmas break (I had a week off) I started to experiment with making some. The Materials are cheap. It works out to a couple cents per tree but I have to warn you, they are time consuming. It takes me about 10 minutes to make a tree. So let's begin:
First we have to make the trunk. I use cedar from a local cedar shingle and shake company. I just went into their office and explained what I was doing and they let me go through their scrap pile. A cedar shingle is about 12" long and slightly tapered. The nice thing about them is it's easy to split. I took my hatchet (never though you'd use one of those in MRing!) and split the shingle until I had sticks that were slightly wider than the pine tree trunks I was trying to make.

First we have to make the trunk. I use cedar from a local cedar shingle and shake company. I just went into their office and explained what I was doing and they let me go through their scrap pile. A cedar shingle is about 12" long and slightly tapered. The nice thing about them is it's easy to split. I took my hatchet (never though you'd use one of those in MRing!) and split the shingle until I had sticks that were slightly wider than the pine tree trunks I was trying to make.