Check out the following “brief” YouTube videos explaining some of the most prolifically used gestures. WARNING: In the second video some of these are a bit explicit, so if swearing offends you, you might want to skip over. However, if you’re planning on spending much time in Italy, you’d better start getting used to creative swearing, with words and hands.
This brings me to share a piece of advice. Embrace the language and do everything you can to perfect your vocabulary and pronunciation, but leave the Italian hand gestures to the Italians. Understand the “vocabulary” of the Italian gestures so that you know when a person is emphasizing a point, expressing outrage, saying someone is bullshitting them, telling someone to go f#*k themselves, or communicating countless other sentiments. But, if you try to emulate these hand gestures, in my humble opinion, you’re playing with dynamite. These movements of arms and hands are so natural and fluid for Italians because they starting learning them when they were starting to walk. Just try reading up on the breadth of hand gestures and soon you’ll realize how you could end up “mis-pronouncing” with your hands. Italians will spot the pretense right away and it won’t be endearing.