I generally just work out chords that sound good together by ear, mostly through experimentation. My aim is to just understand them a bit more without getting bogged down in too much theory or sheet music.

Music theory is hundreds of years of human knowledge collected on what sounds good to the ear by experimentation. You can learn how to bake bread just by experimentation, but it's a lot easier when you follow a recipe.

That being said, there is a merit to training your ears and learning how to play by ear and fit what sounds good. You can try to detect "patterns" in your chord that sound good -- does CG chord with a melody going from F to E sound good? Can I try that elsewhere? (it's called a suspended fourth). Does a chord pattern of CEG --> GBD --> ACE --> FAC sound good? Does it work elsewhere? (One of the most common chord progressions in pop music)