Working With Chord Symbols
Even though it is not necessary at first sight and might take a considerable amount of time, especially when you feel insecure in this, make a habit out of writing down the chord symbols of your piece into your working environment (either in the score sheet or on a chord symbol track in your DAW).
A lot of confusion when learning to compose results in not really knowing what harmony you’re in and trying to figure it out by ear. Gaining control over these things will eventually speed up your workflow and improve your writing.
Also, knowing exactly which harmony you’re in will rule out some things automatically in your head that will not work in the harmony so you will get rid of a big portion of trial and error.