Animal intestines make a superb cordage, but first have to be processed. I usually buy a bag of pig intestines from my local butcher. They are salted to help preserve them, so the first job is to rise them in water.
To the other end I tie a stick and then use the stick to start twisting up the intestine.
The twisting action squeezes the moisture out of the intestine and the twists in the intestine give it added strength. You may have to twist for up to half and hour, but eventually you will feel the intestine pulling your hand as it is tightly wound. This is the time to stop twisting and stretch the intestine slightly and keeping the tension on, tie the end to a tree or fence.
On a dry day, the intestine should air dry in about two hours and can then be taken down, rolled up and stored ready for use. The slight elasticity of the intestine means you can achieve very tight and secure lashings.