You can enable dictionary-tooltip-mode and then hover over a word to see its definition.

We can use dired with wildcards to search for multiple files and directories matching a given criteria.

Example:

M-x dired

~/Desktop/code/*/*/*.js

This will create a dired buffer with all the files ending in .js 2 directories deep inside of the code directory.

We can run M-x find-file-at-point to open the file at point if its a valid file path.

We can use M-x ffap-menu to return a list of all the urls and files mentioned in the current buffer. We can then select an item from the list and navigate to it.

We can use highlight-changes-mode to see text changes that occurred in a buffer after enabling the mode.

We can press s when in a describe key or function help buffer to jump to the source.

We can press the following when point is on an image to manipulate it:

• i+ - Zoom in
• i- - Zoom out
• ir - Rotate

We can use shr-render-buffer to render an html buffer.