Here are some pictures of how I made small "fast"shrubs with aquariumfibers and a piece of floristic wire.
Of course some grassfibes and some fine turf and if necessary some aerosol paint(ratllecan)
For "big"shrubs = max 2 inches in HO scale I use the rough/coarse blue fibres.
These fibres are stiffer as the white green ones.
I use the white green ones mostly for the small shrubs = max 3/4 inches .
The shrubs on the diorama were made with these fibres.
In this "how to" I used the blue stiff fibres but you can do the same thing with any kind of aquariumfibres.
Starting with a piece of floristic wire , about 6 inches long folding together- like a hairpin) in the midlde and some fibres:
Roll the fibers like rolling a cigarette and put them in the loop/between the wires.
Twist the wires tight together so that the fibres will be "locked up". NOT to tight...you will see that if to tight the wires will breake/snap...
Hold the fibres in your - well in my case- left hand and twist the wires with your right hand.
To twist it more tight at the end I use a pincer .
Add a drop of super glue at the base of the shrub and let dry for a 1/4 hour .
it could look like this:
Next step is cutting 1/4 of the fibers and shaping the shrub with a SHARP pair of sicccors.
Try to make the shrub not to dense so cut some(more/many) fibres away in the centre .
Spray the brush in a basic colour, mostly darker as the colour of the "leaves".
Spray some glue over the fibres and add with a sieve the 4- or the 2 mm grassfibres
macropicture of a 1 inch "shrub"
I dont have a picture with a finished shrubb but on the next picture you can see parts of this shrub used on a N scale diorama/module:
a big H0 shrub. I used additional some 6 mm grassfibers andafter that : 2 mm and finaly the Leaves....
last picture also shrubs made the same wat but only cut just above the place where the fibres where glued .....I pulled/tore carefuly the base of the shrub apart so the shrub became more wide.
You can also tear parts of it und use the top of them as very small shrubs
happy "shrubbing"!