The idea behind trussing is to hold the shape of the chicken so it is appealing for presentation. Also, if the extremities (wings and legs) are kept close to the body when cooking, it is less likely they will cook faster or dry out before the rest of the bird is done.
First, rinse and dry off your chicken, and add any seasoning or stuffing into the cavity that you desire.
Cut a 2-foot piece of butcher's twine.
Put the chicken breast side up on the counter.
Take the wings and tuck them behind the chickens "neck."
Take the twine and start by looping it under the neck area, anchoring it around the wing joints. Make sure both side are even
Bring twine around the outside of the drumsticks from below, and start to pull the drumsticks in close to the body by crossing the twine and gently tugging. The drumsticks will cross together tightly.
Wind a loop around the base of the drumsticks to secure, and then tie a knot or bow. Cut off excess string.