Many, but not all, immigration procedures require an interview with an official from the Bureau of U.S. Citizenship and Immigration Services (USCIS). Being prepared and not arousing suspicion will make the USCIS interview as pleasant as possible. The tenor of each interview will depend on the personality of the USCIS official with whom you meet, so it is almost impossible to be entirely prepared.  It is important to remember, however, that it is the USCIS official's job to determine whether there is anything about your background or present circumstances that preclude you from obtaining the immigration status you desire -- the officer does not have anything against you personally. 

THE DOs

DO prepare for the meeting.  Bring copies all of your forms and all your document originals.  You should be able to respond to questions about your forms without extensive referencing and confusion.

DO be prepared to answer personal questions if you are at an interview related to your marriage to a U.S. citizen.

DO follow the directions of the USCIS officer.  If the officer wants to interview you and your spouse separately, that is perfectly appropriate.

DO listen carefully and answer only the question that the officer asks you.

DO bring an interpreter with you if you do not understand English.

DO dress appropriately for the occasion.  This is an important meeting for you, and a good impression can't hurt.

DO remain calm.  If you don't understand the question, ask the officer to rephrase it.  If you really do not know the answer to a question, it is better to admit ignorance than make something up.  It also helps to be prepared.  If you know there is a part of your application that will raise suspicion, practice a truthful response. 

DO show up on time.  USCIS officers are notoriously difficult to reach and requests for changes in interview times are not well received.  If you fail to show up for your appointment, you may have to endure a lengthy process to get another interview.

DO hire an attorney to accompany you if the thought of going through an interview alone is too overwhelming.