I very often create new folder to demonstrate or experiment. Run mkdir, cd, git init, etc; each time when I need is painful. So, I create this simple bash script.

demo.sh

#!/bin/bash

demo () {
  project_name=""

  if [ $# -eq 0 ]; then
    project_name=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 6 | head -n 1)
  else
    if [[ ( $1 == "--help") || $1 == "-h" ]]; then
      cat << EOF
Create new folder within demo folder

Usage:
  demo                    Create new folder with random name
  demo project_name       Create new folder with "project_name" as name
  demo [-h|--help]        Show this help

EOF
      return 0
    else
      project_name=$1
    fi

  fi

  folder="$HOME/demo/$project_name"

  mkdir -p $folder
  cd $folder

  echo "*~\n.DS_Store\nnode_modules\n" > .gitignore

  git init --quiet
  git add .
  git commit --quiet -m 'First commit'

  echo ""
  printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
  echo "Experimental project \"$project_name\" has been created"
  printf '%*s\n' "${COLUMNS:-$(tput cols)}" '' | tr ' ' -
  echo ""
}