Slick is a commonly used word to describe something that is smooth, polished, or sleek. However, there are many other synonyms you could use to spruce up your language. "Glossy" implies a sheen or shine, while "shiny" suggests brightness or luster. If you're looking for a more sophisticated word, you could use "chic" or "contemporary". For something that flows smoothly, "fluid" is a good option. "Sleek" and "polished" both indicate refinement, while "slicked-back" might suggest a certain suaveness or sophistication. "Oily" is another word to use for describing something shiny or smooth, but beware that it can have negative connotations as well.