Play your composition once...stop where you left out and don´t do anything else for 5 minutes...contemplate the new possibilities and where your ear wants to go in your head. GL
It really depends but usually its a mixture of all three of these. But what sucks about it is sometimes I can never remember the idea for that song and it makes me sad when I get to it and I don't even remember what it is. But 7 times out of 10 I can remember what I wanted it to be
Seriously, if I were you, I'd take it one step at a time and focus all your energy on one at a time. Quality over quantity, that's my motto. And you may sacrifice quality if you have too many ideas flying around.
Just my 2 cents, for what they're worth. I hope your composing goes well!
Well, I'm still in high school, but I have taken a music composition class this year and gonna take theory this year. But I've been composing for 2 and a half years. Being in band also helps me out