Here are a lot of upright z-fold cards, but also some "regular" z- or s-folded cards. They sure are fun to make they can be varied in their layout :).
by Brenda Quintana
by Saijai Art & Craft
by Crochet Lovers
by Yonat Dascalu
by Afreen's Creations
by svgcuts
by Michelle Allen, A Creative