How do I create a directory from within Emacs?

• to create the directory dir/to/create, type:

  M-x make-directory RET dir/to/create RET
  

• to create directories dir/parent1/node and dir/parent2/node, type:

  M-! mkdir -p dir/parent{1,2}/node RET
  

  It assumes that Emacs's inferior shell is bash/zsh or other compatible shell.

• or in a Dired mode

  +
  

  It doesn't create nonexistent parent directories.

  Example:

  C-x d *.py RET ; shows python source files in the CWD in `Dired` mode
  + test RET     ; create `test` directory in the CWD
  

  CWD stands for Current Working Directory.

• or just create a new file with non-existing parent directories using C-x C-f and type:

  M-x make-directory RET RET
  

Emacs asks to create the parent directories automatically while saving a new file in recent Emacs versions. For older version, see How to make Emacs create intermediate dirs - when saving a file?

Ctrl+X D (C-x d) to open a directory in "dired" mode, then + to create a directory.