According to series creator Rebecca Sugar, all the voice actors for the Crystal Gems were picked based on their singing voices.
The title character is named after and based on show creator Rebecca Sugar's younger brother, Steven Sugar, who is also the show's background designer.
Rebecca Sugar stated that Estelle, the voice actor for Garnet, helped her write the song "Here Comes a Thought" by giving her songs that calm her down and relax her.
The character Peridot is based on a character from creator Rebecca Sugar's fan fictions of the Nickelodeon cartoon Invader Zim.
Actual Rose Quartz gems have a chance to display "diasterism", which is a phenomenon of gemstones exhibiting a luminous star-like shape when cut. This might explain all of the stars everywhere (the front of Rose's dress, as well as the shirt that Steven always wears).