Note: I've written this post ages ago, I just rediscovered it and thought it might be useful for someone. Personally I've moved away from 3d props due to practical reasons (most of my games take place in places other than my home.
I tend to have numerous terrain projects going on all the time. Sometimes I have difficulties finishing my old projects as I get ideas and inspiration for the new ones, and sometimes I finish these new projects very fast. My trees and swamp project advanced quite quickly, and I upgraded few other older terrains at the same time - more of these later. In this post I'll show you how I created these new trees and pieces of forest that have some wet ground, fitting well into swamp terrain.
The base of these trees is wire. I've been using 1mm wire for larger trees, but it needs a good amount of strength to twist it to right shapes, and it will also kill your fingers. For smaller trees I've used thinner wire. Large tree trunks are just sawed from wooden pole, then I've glued pieces of wire to create roots and used painter's tape to wrap around, then applied filler to lose the tape edges and create more natural form & structure for the trunks. These trunks work very well as a gaming terrain, as foliage is often just a hindrance -consider tops of these trees being hidden for player's convenience.
I've used normal 2mm cardboard for bases, trying to avoid too much moisture to avoid distortion. I've glued thin pieces of styrofoam to create form to the ground and avoid paint's moisture from reacting much with the cardboard that is prone for distortion.
I've just used glossy paint to create watery spots, no more techy there. I've used various flocks to create the surface structure. I've also used real stones and pieces of wood to create trunks, fallen branches and stones on the ground.
For tree foliages, I tried something different this time. I glued green wool to the branches, and then applied dyed glue to these wools, by carefully sprinkling and applying with large brushes, and then rippled large amounts of flock on them. The flock didn't stick as well as I hoped so I had to repeat the process many times, using lighter green shades in the glue after a few layers - I started with darker brownish green hues.