Thinking is like using (at least) one of my senses, but without actualizing the associated physical reality. Right now I can access memories that contain information in audio, visual, tactile and olfactory formats with little effort. I often experience multi-person conversations or music as part of a thought process, but have also known myself to mentally fly around a map, generate pseudocode, mix flavors, sketch an image, or even explore a texture as part of thinking.

...With a little reflection, I find that much of my internal process hinges on something like infographics with little sensory labels, primarily audio but often tactile or even olfactory, but hardly ever actual text. For a complex operation, I seem to zoom in and out on these objects to get the detail/context relationships and see how they interact.