If there are sleeves, they are often frilly (below left) and/or puffy (below right). Collars and bottom hems of dresses/skirts are often frilly as well.
Zig-zagged bottom hems of dresses have varying numbers of zigs and zags. The black dress above had only four points aiming down at the floor, while the red dress above has a dozen or more. And, it's also quite common to have only one: the yellow-frilled dress (below right) has one long side and one short side. If you don't have a dress this shape, it can be approximated by tying a large triangular shawl (or a square one folded diagonally) over your dress, knee-length or a bit shorter, around the waist so its point hangs at your left side, the knot at your right waist.
If shawls, for tying around the waist, are not available, sashes work almost as well. Just a strip of cloth, tied around the waist, and its ends hanging down, can add a lot to your outfit very simply and easily. Above, the red frills were added to a black body suit bought at a second-hand store.
Not all Latin dresses are frilly--the black one above, though slit in many places on the bottom hem, is not particularly fancified. Note the red skirt at right: like all Latin dancing dresses and skirts, it allows the legs to move freely. This freedom of movement comes about in either of two ways: for dresses and skirts with a lot of material (like the red one above), the quantity of material allows the movement; for dresses and skirts with little material (like the black one above), slits must be made in the dress to allow freedom of movement.