Shaping and Slashing
While the flavour of bread is our overriding concern, there is some truth in the old saying, "the first taste is with the eyes". Certainly, for commercial bakers, the appearance of the loaf is important because products that look appealing sell quickly - whether they be loaves, clothes, or cars. However, there is more to shaping and slashing than just making your bread look good. There is something distinctly unsatisfactory about eating a baguette that has turned into an elongated pancake, or a sandwich loaf that is three times as wide as it is high.
Surface tension is the key to succesful shaping. Whether we are making a tin loaf, individual rolls, a baguette, or a batard, the surface tension we impart when shaping is responsible for maintaining the shape height of the loaf as it proves and during the first part of baking. So how do we give our loaves surface tension? The simplest case is a round loaf, or "boule", where the baker takes a lump of dough and pulls a little of it out towards the side, and stretches it underneath and presses it against the underside, then rotates the dough a little and repeats the process until the whole loaf is roughly ball shaped with a central point on the bottom side where the dough pulled from above has been squeezed together.
Other loaves tend to be shaped using an "letter fold" where the baker pulls and stretches one side of a roughly rectangular sheet of dough, using the friction from the worktop as something to pull against so that the loaf surface is taut. This edge is then folded over the middle and pressed down just enough to stick, so that the surface tension is maintained while the other third of the dough is stretched and folded over the top (think of how a letter is folded into thirds to go into an envelope and you'll have the right idea). Finally, the seam where the last part was folded over must be pinched closed either between thumb and forefinger, or with the side of the hand pressing the seam against the work surface. The loaf may be left to prove seam side down on baking parchment or a floured surface, or seam side up in a banneton (basket) which is then inverted to tip the loaf out seam side down just before baking.
It is important to consider the type of bread we are making when we are handling the dough. Stiff doughs, around 60% hydration, such as bagels or loaf tin/sandwich bread, may be handled more firmly than French bread or rustic loaves such as ciabatta which have a more open crumb structure. When shaping the latter type of loaf, the baker must be gentle enough to avoid degassing the dough, so allowing the bubbles that have formed during fermentation to stay in the dough and grow even bigger during proving and baking, giving the finished bread the characteristic holey texture.
You will find more details on shaping different types of loaves in the recipes section and I would also particularly recommend Peter Reinhart's book "The Bread Baker's Apprentice" (see Further Reading for more details).