If you are planning a party for a non-profit organization or a charity event, it is not always appropriate for the gratuities to be prepaid. Most companies add 15-20% to their bills when the gratuities are to be refused from the guests. If you are giving a private party, however, it always is a nice gesture to include gratuities. It is always appropriate to offer a gratuity to the attendants because the host may not have pre-paid for tipping. An appropriate tip today would be $3 to $5 for a good service and perhaps $10-20 for excellent service.