I have been learning Dewani Malaki, it is one of the most beautiful styles I have seen. there is a lot of freedom of expression in this style which I enjoy. Dewani Jali is more decorative in nature. there is no space left in between the letters and ornaments. After writing the letters the spaces are filled with decorative. Dewani is used more for announcements or headings. It expresses Joy or Happiness or any command.