Giving credit where credit is due, I wasn’t formally taught in Orchestration. I have however studied orchestration like a madman. The main two texts I read were Walter Piston’s (Harvard Professor) Orchestration and Hector Berlioz’s (French Romantic Composer) Treatise on Instrumentation. The latter book was updated in the 20th Century by Richard Strauss.
The other resource I use is Dover Publications. It’s pretty convenient for me that pretty much everything non-Metal I listen to was written in the 1800s. Copyrights expire seventy years after one’s death, meaning pretty much everything non-Metal I listen to is in public domain.
Sure, I can download all the stuff for free on the internet, and it’s perfectly legal as it’s in public domain. However, Dover makes some pretty freaking nice books and it’s worth it to buy the books straight from them. I have a pretty good selection of Tchaikovsky, Beethoven, Wagner, Brahms, and Mendelssohn.
Piston’s book I never bought. The local library has two copies of it and I’ve read the thing twice. It’s an easy read. Piston attempts to make it not so dry, despite it being a Harvard textbook.
Berlioz’s book on orchestration
And Berlioz’s book (updated by Richard Strauss) is also a pretty good read. It’s also not too dry. But then again, Berlioz is my kind of man. He’s passionate and borderline uncontrollable. I laughed when reading about him during a riot in Paris running around with a pistol in his hand. The guy definitely lived. Yes, some of the biographies on these Romantic Composers, you have to read. These guys knew how to live life and often had pretty chaotic love lives.
Anyways, I digress. I cannot say enough good things about those two books if you want to get into Orchestration. I am currently self-taught, but that will change before I start writing Concertos, Ballets, and Symphonies. Writing the strings, woodwinds, and brass for Astral Eyes is no easy feat. Don’t get me wrong. But to take it to the High Art level, I will need formal training.