How do you save materials that you create to use them later, in a different project? Say you download a texture files from some website. Then, in blender, use those images in node editor to create a material.

​Or you just use existing nodes in Blender to create your own material.

How do you save that material to use it later in another project? I don't want to open up old projects, search for the materials and copy and paste its nodes it into my new projects. Is it possible to export those materials?
Just save it as .blend and use the append function (Edit>append and select the materials)