Understand why you were invited. Is your friend inviting you? Do you work in a small company, and your boss is inviting you to dinner? Are you expected to attend this invitation? What would the consequences be if you didn't attend?
Weigh the importance of this invitation. There are many social obligations we face throughout life, some more important than others. A social event that typically occurs once in a lifetime, such as a 'coming of age' party or someone's wedding, should have more importance over a night at the movies. How does this invitation rate compared with your existing obligations and priorities?
Thank the person. Someone is taking their time to invite you to some event they feel is worthwhile. Thank the person for their consideration.
Create a delay if needed. If you're confronted in person with a verbalinvitation, respond with a request to check your schedule. This may be communicated within a question, as in "do you mind if I check my schedule and get back to you?", or a statement, "I really need to check my schedule before I commit to anything".
Be honest. To an extent, truthfully give the person a yes or no response. Sometimes a direct answer is desired, especially if the invitation is a social event with an RSVP. Many invitations will have a form on the card to select either yes or no. In this situation, it is not necessary to give an elaborated response. If you're unable or unwilling to attend, simply mark 'no' and thank the sender for his or her invitation.
Follow up with a positiveconclusion. If applicable, let the person know you are interested in accepting the social event at a different time or under different circumstances. Showing interest softens the rejection of an offer.
Accept the first invitation or don't accept any if you received more than one for a particular night that would overlap or conflict.
[edit] TipsInvitations are given for a variety of reasons, but many are positive. Whether given to a friend, family member, co-worker, or acquaintance, it is most likely given because the person cares about you. Remember this when declining an invitation.
If you are really not interested in a social event because it is not your cup of tea, tell them. Regardless of any event's popularity, no one should expect people to have the same joys in life.
If your receive multiple invitations for the same night you should always accept the first one you received. If you decline the other invitations you can let them know you have a prior commitment. Never decline an invitation to one party to attend another one that you were invited to later. You will appear as if you waited for the better offer.
You should never get to a party and complain because of other guest there (ex-girlfriend, old co-worker, or someone you generally don't like). Be a gracious guest, enjoy your host's company, make the rounds and leave early, but do not be the first to do so. Social events are celebrations and you should understand the guest list was not created around your black book.
If you choose to accept multiple invitations for one night you should stay at the first event the longest.
[edit] WarningsDo not repeatedlyrejectinvitations from the same individual or group. Doing so may create a social stigma about you as an individual. If you do have an interest in any of the invitations, accept at least once or express your desire to do so. If not, it is better to state your disinterest ahead of time.
If you declined an invitation to a party you should understand that other friends may have accepted the invitation. It is in very poor taste for you to sit at a bar or other party and text or call your friends at the party you chose not to attend.
Do not be rude or mean when you say no to an invatation.