If you lost the passport or found that your passport was stolen during your foreign trip, you may take the following steps.

1. Before calling the authorities and then reporting your missing passport, you should double-check to see if your passport was actually stolen or misplaced. Once the passport has been reported lost/stolen, the passport will be canceled immediately and its details will be sent to the Interpol’s Stolen and Lost Travel Documents database. As such, you will be denied entry or boarding without the valid passport unless you replace it with the new one.
2. If you are overseas, you must contact the nearest U.S. embassy or consulate as soon as possible to get an emergency passport. Of course, you should make sure that you are ready to pay for a fee and you have your photo and ID readily available at hand. Form DS-64  needed to be submitted for the lost or stolen passport. If you have a copy of the missing passport, you should bring it with you for the application for an emergency passport. Notice that this emergency passport is good only for a year. Once you return home, you can exchange it for a regular one.
3. Best time for passport renewal is November ans the worst time for its renewal is March based on the number of passport applications in the recent past.
4. Be aware that some countries such as France may not allow you to enter those countries with an emergency passport.
5. Be aware that even with a valid passport, you can be barred from entering some countries such as Switzerland that requires travel documents (passport) to be valid for at least three months after your planned departure.

For more details, please refer to https://travel.state.gov/content/passports/en/passports/lost-stolen.html

Guide for smart air travels

1. Research online for travel options, but be sure to talk directly with the human travel provider before booking
2.  Make sure to build in connecting times that give you sufficient time to get to the right gate. Common mistakes are that people are delusional to think that 38-48 minutes of connecting time is enough (although “legal”). At many airports (e.g., Chicago’s O’hare, Pheonix Sky Harbor), the walk between gates are so long.
3.  Consider sending your baggage via couriers such as FedEx, UPS, and others rather than always checking in baggage
4. Tape your ID on the inside of your bag (in large letters, if possible) in addition to putting a luggage ID tag on the outside of your bag that can be ripped. Also, photograph the content of your bag using the smart phone as a caution for the case that your bag is stolen or missing.
5. Check your flight schedule constantly for any delay or cancellation.
6. Print your boarding passes a day before your scheduled flight in case of computer glitches at the airport.
7. Ask your cab drive to take you to the arrival area instead of the departure area which is often more crowded than the arrival area. Also, to avoid the busy airport’s crowd, consider using the alternative airports nearby (Milwaukee instead of Chicago, Oakland instead of San Francisco).
8. Enjoy expedited screening using the TSA pre-check. Passengers who are U.s. citizens and lawful permanent residents can apply for the TSA Pre✓® Application Program to determine if they are low-risk and eligible to receive expedited screening.  There are more than 380 application centers across the U.S. and 44 centers are located at airports. The nonrefundable fee of $85 covers the cost of background checks, when you apply for the TSA pre-check program.  Go to the website: https://www.tsa.gov/precheck