Thank you! I assure you, though, that it's not only talent that's needed. I lack the specific knowledge on how to work with multiple instruments at once, in order to complete a coherent musical idea.
I find this really hard.
Based on my experience.
Here are some advices:
1: Understand the difference between Jazz and media music(film, video or theme orchestra music). This will help you to change the way of thinking about composition and avoiding many problems when you composing.
For me, Jazz has a lot of improvisation and in most cases, melody instruments(piano trumpets or others) are dominant. But the media music (most are orchestra music) is the interactive art between the different large sections( strings, woodwinds, and brass).
a): Timbre change also needs to be considered in orchestral music. For example, the timbre of the violins and flute play the same melody is different from the timbre of the same melody played by the trumpet and the clarinet. The woodwinds section is the group with the most color tension. Different colors can be combined between different woodwind instruments.
b): The transfer of the melody is also very important, do not always put the melody to one instrument or one instrument section.
c): Try to avoid having one instrument section do everything(Unless you only have one string orchestra section).
2:Finding some orchestra music you like and find the scores. Then, do some mockups. You will learn how to use MIDI technology, familiar with the instrument libraries and chord progression, orchestration from the scores.
3:Trying to compose 1 or 2 minutes piece use what you have learned.
4:Learning orchestra mixing.
5:Repeat all the steps.
Hope these will help you out.
Best,
Yuyao