polish up
US /ˈpɑː.lɪʃ ʌp/
UK /ˈpɑː.lɪʃ ʌp/

1.
pulir, perfeccionar
to improve something by making small changes to it
:
•
You need to polish up your presentation skills before the conference.
Necesitas pulir tus habilidades de presentación antes de la conferencia.
•
She spent hours polishing up her essay.
Pasó horas pulir su ensayo.