My personal spin on the right of passage: the maker coin! This one has some thin-walled features that are helpful for testing extrusion width, as well as having multiple colors for dialing in that perfect dual extrusion.
BrentWerderMakerCoin v3 is the single color model.
BrentWerderMakerCoin1 v2 and BrentWerderMakerCoin2 v2 are two parts of the dual extrusion model.
If you print one out, post a make! I'd love to see how it goes.