Early in your trip planning process, check whether you'll need a visa for any of the locations you'll be visiting. It can take some time for visa processing, so it is a good idea to apply for your visa far in advance of your expected departure date. Keep in mind that some countries will refuse to allow you into the country without the proper visa in your possession.
Even if the hotel you wanted to stay at is booked solid, you might be able to score an out-of-service room. Rooms that have maintenance issues like damaged carpets or excessive dirt will be taken out of service until the issues can be addressed.
Always know what is happening socially and politically in all countries you visit. Check online for information and updates about anything happening overseas that could affect your travel plans. This will help you avoid potentially dangerous situations.