The chickens you see at the rotisserie counter, and in famous-chef cookbooks, often look especially neat because they're trussed before roasting. This isn't done purely for its aesthetic effect. It also has practical benefits. Trussing compacts the bird, restricting the flow of hot air into the cavity, which in turn reduces the risk of overcooking the breast meat. Trussing a chicken conventionally with twine takes time and a certain level of skill, but you can achieve a similar effect with no string at all.
Snip open the chicken's packaging and carefully drain any juices into your sink, then transfer your bird to a cutting board and finish unwrapping it. Remove the giblets and neck, if they're present, and blot the bird dry with paper towels, inside and out.
Turn the chicken so its neck end faces you. Grasp a wingtip and fold it downward, then slide it underneath the chicken's neck to place it in a sort of culinary half-nelson. Repeat the same process with the other side, then rotate the chicken on your cutting board so the body cavity faces you.
Season the chicken's cavity with salt and pepper, then fill it -- if you wish -- a peeled, halved onion, a halved lemon, peeled garlic cloves or another aromatic ingredient that will provide flavor as it blocks airflow to the bird's interior.
Grasp one of the loose flaps of skin that can be found on either side of the bird's cavity. Use the tip of a sharp paring or boning knife to make a small slit in the skin. Take the knobby end of the drumstick from the opposite side, and slide it through this new opening. Repeat the process, making a slit on the opposite side and using it to restrain the top of the other drumstick. The bird is now trussed, for practical purposes.
Season the exterior of the chicken and roast it, as you normally would. To carve the bird, simply cut through the thin bands of skin holding each drumstick in place and then bend them down with your carving fork, so you can sever the hip joint with your knife. At that point, the chicken can be carved normally.
Many cooks like to rinse their chickens under cold water, under the misapprehension that they're rinsing off potentially hazardous bacteria. In truth, all this does is spread them throughout the bird, and usually spatter them around your sink and kitchen as well. Accordingly, the U.S. Department of Agriculture's Food Safety and Inspection Service now specifically advises against doing this. You should also disinfect the sink with bleach or a strong cleanser after draining the chicken's juices, to minimize the risk of cross-contamination.