Mostly Oak leaves, White Oak and Burr Oak, from my yard and neighbors, some unknown Oak tree because they came from someone. Tried Guava, liked them, and small pieces of Indian Almond (IAL or IA).
Personally I am cautionary /reserved on IA large leaves because adding them in a big piece like a hand size has caused almost a stagnant condition where they layer and they smelled rotten 2 times the leaves ended up kind of slimy.
I got small size called Betta leaf maybe 5/6 cm and they worked great. Also, later I used slices of a large IAL and they worked alright. ~ 1.5 cm x 6-8 cm / 1"x 4".
Also tried mulberry leaves homegrown from a family member.
Need to pick up a new batch because I used the last of the variety a couple weeks ago, only crumbles left and they are gone now!