The Letter Vav(or Vov) should be 1X3 kulmusim. The top right part of the Vav should be completely rounded, because if it's squared it would look like a Zayin. The face of the Vav should be straight up and down, not angled. Neither the head nor leg of the Vov should be made too long, because then it will look like another letter. (ie- a Reish or a Nun Pshuta). The Tsvei Vov is nothing more than two letters vav.