On this page you find several basic techniques to combine rings.
4 in 1 technique = 4 closed rings are connected with one ring. The resulting element (of which there are many required) is reconnected to a different element until there is a chain of each 2 - 1 - 2 - 1 - 2 rings, etc... These chains are then reconnected to a patch. Multiple patches can form a coat of mail.
8 in 2 technique = 8 closed rings to be connected to two rings. The resulting element (of which there are many required) is again connected with another element until there is a chain of in each case 4 - 2 - 4 - 2 - 4, etc. rings.. These chains are then reconnected to a patch. Multiple patches can form a chain mail (Kings Maille Weave).
Some techniques are difficult to describe. They are often illustrated with small images. By trying it out and seeing it, by trial and error. Practice makes the master.
Inspired? Try it yourself. It takes time, but the result is amazing.