Some books you may find interesting...
"Mathematical Origami" by David Mitchell
"Building with Butterfiles" by David Mitchell
"The Beginner's Book of Modular Origami Polyhedra" by Rosa Gurkewitz and Bennett Arnstein
There is lots of further reading online about 'Mathematical Origami' signposted on Robert Lang's website.
Go to YouTube and type in either mathematical+origami or modular+origami to find inspiring videos about mathematical folding.
You might also like to look at Plaited Origami Models and Paper Folding - Models of Platonic Solids on NRICH.