I am creating foliage sound by different types of dried grass, leaves, fake plants, etc. I am having a major problem though because after I put them into my DAW and hear them through my studio monitors they sound a little brittle sounding and for the leaves will be almost a small "hiss". Are there any tricks to fix this problem? -Thanks for the help.
There's nothing especially wrong with what you have there, but perhaps it's not the right sound for what you need it for. The sound of foliage rustle, particular sounds like wind in trees just does sound like filtered noise, such as this as an example:
I'm guessing that the stuff you recorded is also quite small and so will produce quite delicate sounds. There's no exact answer as I'm not sure exactly what you want, but perhaps try the following and see if you can find a solution from it:
Record lots of different types of foliage. Branches with bigger leaves will a different, more defined sound than the smaller stuff.
Don't just record stuff with lots of leaves, pot plants with bigger leaves have a different sound too. There's nothing to say that what you use for a film scene needs to be accurate, it just needs to sound right.
Probably the most important thing - vary your recording angle and distance a bit. Getting closer will give you a fuller sound which may work better for some stuff. Two mics at different distances is a good call.
Don't forget that stuff will get layered in post anyway, so if there was a scene with some people walking through foliage the editor will cut in a background or two, then different spot sounds for the action on-screen. But the first section of that file you posted would be fine for medium perspective leaf rustle.
Hopefully that helps!
ps. If you're providing library style recordings, hten provide them untreated, but also if some sounds are too bright they can be filtered, so don't worry about that.