A v neck that draws the eye in a vertical line will elongate the torso. Sleeveless works, if you're comfortable baring your arms, and so will 3/4 sleeve or long sleeves. Be careful with short sleeves, as they can add bulk to your shoulders and visually shorten your body by drawing the eye up and out. Try something like this flounce tbd Crisscross Blouson Top, $57.90 at Nordstrom.