Document every aspect of your lives together
From first meeting, to courtship, to engagement, to marriage and beyond, collect and maintain every possible scrap of paper you can to show that you live together and have a shared life. Keep copies of e-mail correspondence, cell phone records, occasion cards between the two of you. Make certain that leases, property titles, tax returns, bank accounts, credit cards, life and health insurance, and other records are in both names and reflect your marital residence. Ask your employer to update your personnel files to reflect your marital status and name each other as your emergency contact. Get a digital camera and document your lives together- at home, on vacation, at family gatherings, at restaurants, etc.
Let the world know about your marriage
Immigration officers suspect marriage fraud when couples keep the fact of their marriage a secret from family and friends. They also suspect fraud if public agencies continue to list separate addresses- make sure your bank, Department of Motor Vehicles or Secretary of State's office update your records to reflect your shared residence. Update your Facebook pages to show you are married. Try to maintain a healthy work-life balance and be sure to cultivate friends outside of the marriage who can later testify about what they know, if necessary. If possible, visit each other at work and introduce each other to your co-workers. Participate together in community, religious and social organizations and functions. Photographs of the couple are fine, but photographs of the couple with family members and friends in a variety of settings are much better. The more people with whom you share your lives, the more evidence you will have to overcome a USCIS fraud finding.
If USCIS finds fraud, get the facts, consider the options, and seek legal help
Where USCIS thinks there has been a sham marriage, it will deny the I-130 petition, I-485 adjustment of status application, I-751 petition to remove conditions on resident status, I-360 Special Immigrant abused spouse petition or N-400 naturalization application. Seek a copy of the administrative file through the Freedom of Information Act, fully review the reasons behind the denial, and prepare to contest it. The couple or the noncitizen may be able to refile with better evidence or appeal an adverse decision. In all cases, it is wise to obtain representation from an experienced immigration attorney.