This is a version of a Post-It (Sticky) note holder I found on Printables.  I was nearing the end of a spool and wanted to see how much I could remove from the model without it losing any integrity.  It can be further reduced, but I liked the way this looked.  It reduced the amount of filament used by around 35% (43g down to 28g according to slicer estimates. 

I printed with a 0.3mm nozzle, 0.3mm layer height with no supports.  There was only a small amount of cleanup from not having any supports, as the photo shows.