These are the trees for the motorway junction base. They were made bottle-brush style; bend apiece of soft iron wire into a hairpin shape, cut green parcel string into two inch lengths and tease it out into individual threads before placing them between the arms of the "hairpin". The hairpin is then twisted between two pairs of piers to make a brushlike tree.
These pictures are after I tried some further improvement. Basically I stuck each tree into a ball of bluetac to give me something to hold and a way to stand them up to dry. Then I heavily sprayed each tree with matt varnish (Army Painter "Anti-Shine") to the extent that it started to form beads on each branch. I then dipped each tree into a container of fine flock and sprinkled on more flock if required. Finally each tree got a light spray of the varnish that I hope will help fix the flock in place.
Here they are drying on my shelf.