How to make grass foliage?

I’m looking for the royal road on how to make good looking foliage, especially grass (I know, trees are done in SpeedTree). Is there some kind of a tutorial/series on that showing every little necessary step from thinking of how it should look to tweaking it in the engine until it really looks great?

Thanks!

Guide to use Speed Tree to make grass and other small effects like bushes;

Didn’t know you use SpeedTree also for grass. Thanks a lot! Exactly what I’ve been looking for.