A simple modular origami by Nina Ostrum.
A very sturdy and easy to make vase by Philip Shen.
A fairly easy modular by Dennis Walker.
This Froebel star by Froebel Friedrich is made from 4 strips of paper.
A shuriken like modular star by Robert Neale.
An action model made from 8 Tung Ken Lam’s jitterbug modules.
A modular origami which lets you make a cube, an octahedron, an icosahedron and so on, by Stephan T. Lavavej.
Hexaflexagon action model, by Paul Jackson
A very good modular for beginners, the modules only need 8 creases.
Here’s a very easy icosahedron by Heinz Strobl.