I've been lurking Pinterest, and came across a few tutorials by fellow miniature makers on how to make realistic (non-hobby shop) grass on the cheap- this is my experience with my take on the methods I came across.
I started by cutting out a little rectangle from cheap-o craft wood, then covering it with a scrap from an old sand-colored grass mat. Some big grain sandpaper or even just sprinkled sand would work too.
I knew that I wanted the base to be somewhat dead-looking and colorless (all the more creepy and ringwraith-y), so the light sand made a good bottom layer.
I then reached for my handy jute twine (a few bucks at Rite-Aid), and the jute twine I'd dyed green back when I was working on the micro water jump. The dyed twine was just cut into two inch long sections and left to soak in dark green Rit dye overnight.
A badly-lit comparison of the regular twine and dyed twine; the dye made it a lot darker, but the green is very natural looking and blends well with the undyed tone.
The next step was to snip off teeny tiny slices of the twine, probably about a millimeter each, into a Dixie cup. Ta-da! Micro scale blades of grass. I chose to use a mix of the undyed and green twine to get a nice mix of tones.
Using an old wet paintbrush, I took some Tacky glue and dabbed along the edge of the base where I wanted the grass to be.
Tacky glue dries fast, so I sprinkled the grass on as I went to make sure it would be "grabbed" by the glue.
...And sprinkling the grass on.
A good tip is to leave all the grass on top of the glue until it dries completely, instead of immediately tapping off the excess. Again, to get the maximum amount of grass actually attached.
After dumping the grass on the glue and letting it dry, I was left with this:
I found the twine bits to be really static and they didn't really want to come off with just the normal tapping. I ended up using another old paintbrush to gently brush away the excess grass sitting on top of the grass actually glued to the base.
On the top is the side I've brushed, the bottom still has all the excess grass:
And just the secured grass!
While this isn't a bad-looking base on its own, I wanted to keep playing with it.
Taking a tiny bunch of twine and snipping off a 5mm length, then sticking that bunch into a dot of glue on the base led to some nice grass tufts:
After letting those dry completely, I went back in with my scissors and old paintbrush and fussed with them until they looked a little more natural:
And the final step was to take a tiny bit of dark brown pastel dust and give the sand base some lowlights and depth:
I ended up painting the edges of the wood black, too.
Ta-da! Teeny tiny grassy path, fit for a teeny-tiny Nazgûl to gallop down.