With facial movements we can express a whole range of emotions, from the deepest to the most superficial. If something is bothering us, our annoyance is reflected in a hard or angry facial expression. The human face has a tremendous variety of expressions. If we consider the head as well as the face, we find another whole set of movements. You can nod your head, shake it, turn it away, and raise it sharply; all these movements are significant.

http://www.bvsde.ops-oms.org/tutorial6/i/pdf/topic_05.pdf

If your topic makes you feel vibrant it shows throughout the speaker

and it is contagious

An inner vibrancy that reflects throughout face and body transmits a feel of emotional truth in the experience or idea that is being conveyed.

The topic is the central focus. However, gesticulations such as movement of the hands and eye contact should be central in presentations.

A large amount of the communication between the speaker and the audience is non-verbal. When I teach public speaking, I teach that the speaker must make good eye contact, which means knowing the subject very well and NOT reading a script word-for-word.

I teach that the speaker should use gestures naturally to reinforce the message.

I teach that the speaker should not stand behind a podium, but rather should use the space naturally, using movements from place to place to highlight changes to each next main point (i.e. do not pace, use movements strategically).

I teach control of body language, such as NOT shifting weight between legs, not keeping hands in pockets, etc.

And vocal qualities are also part of non-verbal communication, so speak from the diaphragm, use strong inflection, and vary the pace to slow down for the important words.

Different body language can mean different things in different cultures...but I think smile can never fail, in any culture

I appreciate Mirna Leko-Šimić's concern for the specific cultural context where communication is taking place. This is the subject of existing literature, for instance Power & Galvin's:

Article The culture of speeches: Public speaking across cultures

Make sure your use of body language (the full gamut, body, eye contact, hand gestures etc...) match the associated meaning of your speech.

for example, a good all inclusive hand gesture could be seen as a revolution of both your hands in a circular movement.

If you can, sense speeches are typically broken up into 3 or 4 bullet points, try to notice which bullet point resonates with which judge and when explaining that particular topic, devote more attention to the judge in mind.

One key component in effective communication in public speaking is something that Obama (love em or hate em) did so well, and that was the use of his fist clinched but his thumb as use as a pointer to the audience. An example would be "so when you" and do the hand gesture to the particular judge.

As a footnote, when memorizing a speech try to symbolically represent the words in your mind or else it can be seen as just reading from a script. your speech is your speech. typically I find these kinds of questions as lack of ownership to the speech in general. truth is you won't know the judges, their background etc... so, if your anxious it's probably because your trying to get in their heads beforehand.