Woodland Scenics do a range of plastic tree armatures for different scales. What will function as a tall tree in one scale will work as a shrub or bush in a larger scale.
The armatures come in two parts. A rather flat tree armature and a stump/base. As I am going to be gluing them to Renedra plastic bases, in a number of cases I have removed the peg from the bottom of the armature, drilled and pinned with some 1.5mm plastic rod.
As you can see, the armature is rather flat. It is easiest to clean the mould lines (of which there are many) while it is flat. I warmed the plastic with boiling water (you can also use a hairdryer) and the application of brute force via a pair of pliers.
I rotated each branch such that the whole thing made a near circle. The base of the trunk and the Renedra base was drilled and pinned with 1.5mm plastic rod, and glued with copious quantities of liquid poly. Once dry, the trunk was painted with Citadel Agrellian Mud technical paint (it cracks to simulate bark).
The base was sprinkled with Woodland Scenics Fine Cinder Ballast and some granite ballast for additional texture.
The whole thing was sprayed with Citadel Chaos Black.
The trunks were painted with various brown and grey shades from a wet palette, dry brushed with Citadel Terminatus Stone and then washed with Citadel Agrax Earthshade. The bases were painted with Vallejo Burnt Umber.
The foliage on the trees is Woodland Scenics Green Poly Fibre, cut into clumps and glued using PVA applied to the branches.
The bases were decorated with a mixture of Peco Patchy Grass Tufts, Gamers Grass tufts, various shades and lengths of static grass and fine turf (minced sponge).
Some of the "trees" were shortened by cutting the trunk with a razor saw just below the first branches. This was to give them a more shrub or bush like appearance rather than being short trees.
Some haircutting is required to trim the more "fly away" bits of poly fibre.
There is the question, do I add "leaves" to the bushes, either using fine turf or some cut out leaf material?