Lisa started to go on a tangent about how she tries to avoid hexes and jinxes because unicorn tail hair doesn't respond well to being mishandled and her wand really prefers to be used for positive means and can get sort of moody if she performs too many negative spells with it--which is an important thing to consider, Professor Carrow, because you want your wand to be able to perform at its peak no matter what you're doing, so if a wand is prone to melancholy following a hex or a jinx, it's a good idea to cleanse its palate with several positive spells like cheering charms or something similarly uplifting.
"Like this," she said, and demonstrated a tickling hex on her bear and followed it with a cheering charm.