In my ~/.bashrc, this works well for me. I did have to add --restrict-filenames after encountering some sites using really long titles that were problematic.

  ytdl()
  {
    mkdir /tmp/ytdl && cd /tmp/ytdl
    for URL in "$@" ; do youtube-dl -o '%(title)s.%(ext)s' "$URL" --restrict-filenames; done ;
    mv /tmp/ytdl/* ~/Desktop/
    rm -rf /tmp/ytdl
    exit
  }