You asked for a more general approach, so:
Rule Number One: Inform yourself about your destination.
Inform yourself about the people and their customs(!) and the
respective laws(!!). This cannot be stressed enough because
there are still people out there who believe that they can
behave like in their home country and that the home law still
applies. This attitude can kill you or give a very long prison
sentence in countries like Singapore or Saudi-Arabia.
No, "I did not know that!" does not work. It is also not
recommended to puff up oneself and believe that problems are going
away if you complain loud enough.
Important is at any case the location of embassies (if you lose
your passport or need general help from your home country) and
how ambulance, police and transportation is working in the
Rule Number Two: Get all documents.
Everyone knows that you need a passport, but there are often other
documents needed, so I give a short list of the ones who are often
- Visa: As everyone here knows in painful detail, people try to
travel to countries where a visa is needed and already bought a flying
ticket. Then they are horrified that they do not get a visa and their
ticket is worthless. Don't do that, get first the visa, then the ticket.
- International Drivers Permit: You want to travel inside the country
by car? While there are countries which allow you to drive cars with your
home license for a limited amount of time, for most countries you need
an IDP which allows you to drive cars. Don't forget Rule No. 1: Inform
yourself about the traffic laws and the traffic situation.
- Vaccination certificate. Some countries only allow people to enter
which have been vaccinated against specific diseases.
- Credit card/Debit card/Cash. While you don't need a credit card at
all in e.g. Germany, holiday in the USA will be almost impossible
without a credit card. Some third world countries do not accept credit
cards at all (and if they accept it, watch out. One joker in a bank (!!)
tried to booked the money two times). Sweden on the other hand is almost
cashless. So inform yourself what money form is available.
Rule Number Three: Don't forget important things and arrange a channel of communication if things run bad.
Because you cannot get things once your plane lifted off, you must be sure that you have everything inside your luggage. I have a list of things which I tick off when I travel. Please also look that you don't put forbidden things in your hand luggage which will be confiscated at the airport. I also have a list of phone numbers/emails of different people if something goes awry and I need help or inform others what happened (Or if something happens to me, police/ambulance can contact my contact persons). Don't use a single person because it is a single point of failure: The person can get sick, have an accident, whatever.
Have a nice holiday.