Got this design and was asked to produce an outdoor riverside rendering. Im not fully happy with it yet but I'm liking how its going. It needs more refinement and stochasm to help drive the realism, but for my first real blender archviz attempt with all assets and shaders my work I'm pretty happy with it so far.
Sure! I found some grass clump models somewhere, they are basically just little tufts of grass of various different orientations and arrangements, very low poly but from a distance they work.
Then I selected the ground plane I wanted to apply the grass to, and in edit mode selected only the areas to apply it to (you can do this using weight painting or vertex groups, I will encourage you to look both those up if you're not familiar).
Then using particles I made the ground plane an emitter for hair particles, but switched them out for a collection which contained all of my grass tufts. It took some time to orient each grass tuft object so they were position with z upward, but in the end I figured it out.
Theres a number of great tutorials on youtube about this technique that would probably do a better job explaining. This video seems really good.