Introducing origami beetles from Yamaguchi Makoto’s book The Beauty of Origami
I would highly recommend this book, it has clear and concise instructions for a wide range of origami animals/creatures and covers models from beginner to more advanced levels.
Here I'm using a model of the Japanese Rhinoceros beetle as a sample to show you how to add extra shaping to the insect’s legs and give them a more realistic look.
For this beetle I used two sheets of 15x15cm Tant paper, this type of paper is good for shaping as it holds the fold really well, but you should take care when folding several layers at once.
To make the leg look more realistic and 3D, you need to perform two separate folds along the leg. This type of folding is known as a pleat fold.
First, perform a mountain fold along the dash dot dash (- . -) line at the top end of the leg
then perform a valley fold on the dash line ( - - - ), making it skinnier the further you get towards the end of the leg.
You can curve along where you performed the mountain to give it a rounder look, then curve the edges of the leg.