To give sparkle to a nail design, use

Using gems in a nail design is an effective way to add sparkle and visual interest. Gems can catch and reflect light, contributing to a dazzling effect that enhances the overall appearance of the manicure. This approach is particularly popular for special occasions or when someone wants their nails to stand out, as the facets of the gems create a brilliant shine.

While applying clear polish can provide a shiny finish and help protect the nail design, it does not add the distinct sparkle that gems do. Similarly, smudging the polish would detract from the overall appearance rather than enhance it, and adding different colors could change the theme or aesthetic but would not directly contribute to a sparkling effect. Therefore, gems are the most suitable choice for achieving that sparkling touch in a nail design.