Major vs. Minor Keys in Music begins with a clear listening goal. Major and minor are starting colors, not complete emotions. Rhythm, register, harmony, and timbre can make a major-key track wistful or a minor-key track energetic.
In practical terms, this means making one decision at a time and checking it against the musical purpose of the track. Avoid copying a technique simply because it is common: context, genre, and the listener's attention determine whether it helps.
The most reliable way to develop this skill is to work in small, repeatable experiments. Write the same motif over a major and minor tonic. Keep the rhythm identical and listen for which notes become expressive; this develops an ear for tonal context.
Before calling the work finished, compare it at a comfortable level with a relevant reference. Listen for the intended feeling first, then for balance, clarity, and whether the strongest musical idea is still easy to find.
Keep the result in context with the rest of your track. A good production choice supports the song's rhythm, emotion, and focal idea, then leaves the listener with a reason to come back.