How do you make good displacement grass?

I’m familiar with displacements, and I’ve set up rudimentary displacements in the past, but I can’t get my displacement grass to look good. I’ve read through this and the developer wiki displacement article, but the prior guide misses important details, like roughly how big each grass face should be; trying to make a gigantic brush into a displacement, even at 4, is not ideal at all, but I don’t know how to cut it down to look nice. Furthermore, when I do cut the grass into little chunks and make them separate displacements, I need to sew them together to prevent leaving obvious holes in the geometry. The result is that the seams between displacements become extremely obvious, overshadowing the displacement work to begin with.

I’m running VIS and RAD on the fast setting because the computer I’m stuck with right now is not the best, but I doubt that’s the problem. What tips do you guys have on making these displacements? Because the one guide I managed to google up omits way too many details…

see if this video helps u out http://www.tophattwaffle.com/hammer-trouble-shooting-3-shadows-on-displacement-edges/

Make sure they are sewn together.