Maybe don't use synths for getting your ideas down.

If I have the beginnings of a song in my head, or I have been humming to myself, sometimes I just record the parts I have as vocals - humming or full-on beatboxing the bass/strings/lead/beats separately and as close as I can make them to my head-song (including filters with my mouth)- and then replace as I go, figuring out how to achieve the sounds that were in my head.