I am fantasizing about being able to pull off a lovely homemade horchata. The last time I picked up a premixed bag of horchata ingredients at a Salvadoran market once, and followed a friend's grandma's preparation techniques, I ended up with gritty, bland water. I'm more than willing to track down interesting components for an authentic recipe...but I obviously need better technique.
I understand that recipes vary widely---I'm keen to try them all! Please share your favorite.