So I've had a few requests in the comments here to explain how I made the forest floor bases on my Huntarr. Pictures = 1000's of words etc.,so I've put together a quick demo.
Most of the materials I use: oregano flakes, a stick, paints, white glue and clear coat. I'm using a 25mm base for visibility.
Some cut-up pieces of stick become broken saplings and logs on the
ground (I forgot to take a pic of this step). For 15mm scale you don't need to cut these very carefully. Glue them down with epoxy or white glue... crazy glue will just soak into the wood.
The basic cover of oregano is laid down by sprinkling over white glue. This will generally need to be touched up by adding single flakes to fill the gaps. Then, a tool is used to squish the flakes down and compact the surface.
The leaf litter is liberally soaked with a mixture of acrylic matte varnish, brown, green and black paint. This will darken it and help to physically consolidate it.
The litter is drybrushed with lighter greens and browns, all mixed with a light tan to desaturate them. The logs are just drybrushed with bleached bone.
This should all give you a passable jungle floor for 15mm, or even larger scales if you are a bit fussier with how it looks.