The individual style of each of the Ballroom and Latin dances is integral to defining the movement and feel of each dance. But more than in any other dance, the style of Tango is what makes it dynamic and unique. Without style, Tango is simply walking around the room.
Most people, when thinking of the tango, think of the rose in the teeth and one arm pointing dramatically in the direction of travel. Although this is a common stereotype, there is little to back that image up technically. The hold for Tango is more compact - rather than stretched - and the drama does not come from the presence of a rose.
Instead, it is the quality of the movement that you should focus on. Tango has a feeling of "stalking" to it. Your knees should be bent at all times (imagine the ceiling is 2 inches above your head) and the impetus to move comes from your core - not your feet or legs. It is very important that you do these things technically, though. When I say your knees are bent, that means that you need to keep your hips under your shoulders and simply allow your knees to move forward over your toes rather than remain over your heels which will cause your bottom to stick out. Posture is exceptionally important to maintain as the dance just wont look right unless you keep your shoulders broad, collar bones lifted, and heads to the left (ladies more left than gents).
Ladies, dont forget that your Left hand is not on the gents shoulder as usual, but instead is placed behind his shoulder - sort of like a karate chop with your thumb ending up at his armpit and the palm of your hand facing down.