I'm leaving in a couple of weeks on trip to Belgium and Holland, and here are some suggestions as to what I do before leaving; others might have similar, or additional, thoughts:
1. I prepare an itinerary with hotel names, locations, phone and fax numbers, in case someone needs to contact me while away. I leave a copy with my wife and take one with me.
2. I make a copy of my passport and keep this in separate place, and leave copy with my wife, just in case I misplace mine.
3. Before I leave I prepare a list of items I need to take, such as passport, foreign currency (if I have any left over from previous trip), bank ATM card, 1-2 credit cards, driver's license, camera, medicine, electrical chargers (phone, camera) with country converter-plug-in, and check these off as I pack in luggage.
4. I call the mobile phone carrier and order one-month, international travel talk/data plan, and I disconnect my "Data Roaming" in foreign country until I need to access email, phone GPS, etc.
5. I change my office and mobile greeting to advise I'm out of office and to contact me only in emergency.
6. I've prepared an emergency list entitled "In Case I Don't Return", with all my insurance policies and respective contacts, investment lists and contacts, list of all passwords, lawyer/accountant contacts, social security number and contact, etc., to minimize my wife's (or family, if she's traveling with me) having to search for all these details.
7. I check to make sure my insurance provides coverage in area where traveling and supplement with travel insurance, if needed.
8. I provide the airline on which I'm traveling with family contact.
9. I record international numbers of car rental, hotel and airlines in case I need to contact them while in another country.
10. If I'm leaving for a "hostile" area - such as certain places in Africa - I contact the U.S. Embassy to advise travel plans.
11. Lastly, but actually the first thing I do is pray for traveling mercies!