For making something smooth and shiny:
* Buff: (verb) To make smooth and shiny by rubbing.
* Shine: (verb) To make something bright and reflective.
* Gloss: (noun) A smooth, shiny surface.
* Burnish: (verb) To make something smooth and shiny by rubbing.
* Varnish: (noun) A transparent liquid that forms a shiny protective coating.
For improving something:
* Refine: (verb) To make something more perfect, elegant, or accurate.
* Perfect: (verb) To make something flawless.
* Enhance: (verb) To improve or intensify something.
* Improve: (verb) To make something better.
* Develop: (verb) To make something more advanced or sophisticated.
For a language or skill:
* Refine: (verb) To make something more precise or elegant.
* Sharpen: (verb) To make something more acute or effective.
* Perfect: (verb) To make something flawless.
* Master: (verb) To gain complete control over something.
Other options:
* Smooth: (verb) To make something even and free from bumps.
* Clean: (verb) To remove dirt or impurities.
* Prepare: (verb) To make something ready for use.
* Finish: (noun) The final stage of a process.
Please provide more context about how you're using "polish" so I can give you a more accurate suggestion!