Ornamental grasses are a prominent feature of the late summer and autumn garden -- the more common Calamagrostis (Feather Reed Grass), Miscanthus (Maiden Grass, or Chinese Silver Grass), or Panicum (Switch Grass) are common, easy, and useful plants.
One slightly less known is Molinia (Moor Grass). A noted feature of most varieties within this genus are their "transparent" or "semi-transparent" habit. This is in reference to their relative low mound of foliage, and much taller but loosely-bunched "flowering" stems, through which the observer can see plants in the background.
The above shows the "semi-transparent" nature of Molinia 'Variegata' with Physostegia (Obedient Plant) visible behind it. Generally, the non-variegated varieties are even more useful for this purpose.
The above is Molinia 'Variegata' in all its glory on its own.
Here's to dirt under your nails.