Summarize:

Common gestures allow you to bypass concepts you'll have to express each turn, like categories, so you can get to the good stuff. But it would be unfair if a few players didn't know these, so run through common gestures with all players before starting. Because every word or phrase will fall into a category, it helps to have standard gestures for these. This way you don't have to waste time thinking up a unique gesture on the spot and can instead focus on gestures useful for the words on the slip. Indicate book titles by unfolding your hands, as though opening a book. Gesture as though you are cranking old fashioned camera for movies. Draw a square or rectangle in front of you to signify TV shows. Pretend to sing (without actually singing) for song titles. Pull on a rope to raise a theatre curtain to indicate plays. Make air quotes with your fingers when your slip has a quote or phrase. When a teammate is close, allow excitement to show on your face. Use the distance between your fingers or hands to indicate closeness. To discourage teammates on the wrong track, point at them and shake your head "No" or form an X with your arms. If a teammate is on a roll and they seem like they might say the right word, use a beckoning "come here" gesture or roll your hands in a circle. Moving your hands farther apart usually means "more," but in some cases, this can also mean the word is "bigger," like when it has a prefix or suffix. In some situations, your teammates might have the right word, but it might not be in the right tense, or it may need to be plural when they've said it in the singular. When a teammate is close, point to them and then: Link your little fingers together to indicate a word is plural. Wave your hand behind you in a "way back" gesture for past tense. Do the opposite of this for future tense. By cupping your hand to an ear, you'll signal to your team that you're only acting out a word that sounds like the one you're working on. After that gesture, if you pointed to your eye, it would be obvious the word you're working on is "I." The faster you clearly gesture, the more quickly your team will be able to guess your phrase. Practice by playing Charades often so gestures come to you naturally, without wasting time thinking. If you have difficulty clearly expressing yourself through gestures and you really want to get good, take an improv class or a mime class.
Discuss common gestures with all players. Express categories with standard gestures. Encourage guesses on the right track. Guide teammates to the right tense or form of words. Use similar sounding words to your advantage. Improve your game with practice and speed.