Here is a brief guide to putting together my trees:

On the right is the artificial ferns as they come from the shop, 4 to a piece. On the left is a single item cut from the main body.

I then wind several layers of garden twine around the stem, making it slightly thicker at the top and bottom. This forms the trunk.

The whole trunk is covered in PVA glue and smoothed from top to bottom.

A simple basecoat and single drybrush in a lighter shade. The "stringy bits" hang down (If you smoothed it!) and add texture.

The finished, based tree, with a Copplestone adventurer to show how they measure up.