A few things shape how a pinky ring is worn day to day.
The pinky is your smallest and usually most tapered finger, so fit matters more here than anywhere else. A ring that is perfect on your ring finger will almost always need sizing down. Creating a made to order piece helps, because it will be crafted to your individual measurement rather than guessed.
Gold signets and chunkier bands suit the pinky well, since the proportions of the finger let a bold design really stand out. A diamond pinky ring catches light in a way people notice, mostly because nobody expects sparkle there.
If it is meant as a friendship or self-promise ring, think about custom engraving the inner band. A date, an initial, or a single word that only you know is there.