Whenever I have the thought, "I don't know much about..." then I can make a list of what I do know about it. It turns out, then, that I know more than I thought I did.
So today's topic will be orchestration.
My first thought is that you would know have to know the range of instruments. There would be low, like basses and tubas, then medium low, like trombones, bassoons and cellos. Above that there are violas and other things in that range, and then violins, oboes, and flutes at the very top. Clarinets have a wide range. You would have to know the exact range, and comfort levels of each instrument, along with timbres and how they blend or stick out.
Then you would have to know how to write for strings. That is the meat and potatoes level. You'd have to think about functions of other kinds of instruments. Are they soloing or offering timbral richness to a chord? You'd have to think structurally about what the piece is doing at particular moments, and about the total texture you want.
You would have to know harmony, voice leading, and the like. How to orchestrate chords between instruments. Voices can be doubled, or not. You would have to know when to leave out certain instruments.
So I don't know much about, but I know something about what I don't know about it. I know what I would have to learn in order to know about it, or actually do it. Of course, deeper into the subject I would discover more things that I'm not thinking of right now.
Try this with a subject that you don't know anything about. Or suggest one to me. I will tell you what I don't know about it.