Please use the handset of your phone instead of your speaker. Hearing your communal conversation from across the office (down the hall, on the next floor etc.) is disruptive.
If you need to have a hallway (aisleway) conversation, please keep the volume under control or be aware of others using the phone.
Be aware of any habits that might annoy or disrupt those around you. Example would be the office mate who, at random times, begins banging his/her mouse on the desk or stomping their feet on old wooden floors. Included in this would be loud grunting continously, or making noises like a pinball machine. (This does not include someone who cannot help it for medical reasons, just those that do it out of years of unconscious habit).