Tune around the runs
Automatic tuning can treat a fast run as a series of mistakes. Anything pulling toward the nearest note can flatten a slide or blur a melisma. Fix only the notes that sit wrong, and leave the movement between them alone.
Point the producer at specific lines and say what to protect, such as the run at the end of the second verse. Blue notes and bends are often the point. Keep the untuned take and compare them directly: if the tuned version feels less like you, pull it back.
Build stacks with a plan
Stacked harmonies are central to the sound, from a single line in a verse to a full block on the hook. Sing them yourself if you can, because small differences between takes make a stack feel human. A generated harmony is a quick way to test an idea before you record it.
Layer from the lead outward. The closest harmonies stay near the center, wider ones sit further out and the softest ad-libs sit furthest back. Keep the S sounds in the stack under control, since a dozen of them at once can make a hook harsh even when the lead is fine.
Warmth and space, not polish alone
A smooth vocal usually comes from controlled dynamics and a gentle top end, not heavy brightness. Several stages of light compression sound more natural than one stage doing all the work, and a plate or room reverb can place the voice in a space without pushing it back.
Keep the bass and chords warm, and leave room in the low mids so the voice does not sound boxy. R&B covers a wide range, from classic soul to sparse modern records, so name the era and feel you want or share a reference. A sparse track exposes every flaw, so check the quiet passages as carefully as the hook.
Common questions
Will pitch correction ruin my runs?
It can if it is applied to everything. Ask for targeted correction on named notes and compare the result with your original. The untuned take stays in your project, so you can always go back.
Can Dhun sing my harmonies?
Dhun can generate a harmony part from your lead vocal once it knows the key. It is useful for testing an idea, and a harmony you sing yourself will usually blend more naturally.