You can make those with Blender easily. Using Blender to design a small object to send to a 3D printer is like using a bulldozer to build a sand castle. You can do it, but it’s overkill.

If you’d rather twist in CAD, we can help. If you really want artsy 3D printing, you probably need to learn Blender.

"[Blender] is daunting at first ... By contrast, Cura is a free 3D "slicer" program that converts digital models into layers that can be sent to a 3D printer.