Popsugar Entertainment Pretty Little Liars Pretty Little Liars Halloween Costume Ideas Have a Pretty Little Liars Halloween With These Costume Ideas October 17, 2017 by Ryan Roschke View On One Page Photo 9 of 27 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 9 Spencer Hastings What to wear: Spencer definitely has a preppy style, so any way you want to emulate that is your choice. How to act: Smart and sophisticated. Spencer knows what she wants and exactly how to get it. Previous Next Start Slideshow Pretty Little LiarsHalloweenHalloween CostumesPop Culture Halloween CostumesTV