The definition of etiquette is defined by Merriam-Webster.com as, "The conduct or procedure required by good breeding or prescribed by authority to be observed in social or official life." In other words, proper etiquette is basically good manners as defined by society and culture.
There is nothing complicated about following proper etiquette, but everyone slips up and makes mistakes. When this happens to you, own the mistake, make apologies, and do your best not to repeat the behavior. Your family, friends, coworkers, and supervisors will appreciate your attention to the fine details of following proper etiquette rules.