Keep the information hierarchy short
A lower third usually needs a name and one supporting line. Add an organization, role, or social handle only when it helps the audience understand why the person is speaking.
Respect the footage and safe area
Place the card away from faces, captions, and platform controls. Use a background plate or shadow only when the footage makes the type hard to read.
Use consistent entrance and exit timing
Bring the lower third in after the shot settles, hold it long enough to read twice, and remove it before the edit becomes visually busy.