1. Buy an international SIM card
Consider this a top priority. Of course, your phone number will change, but everything else remains intact. Some companies (Maxroam, Telestial, Truphone) will let you purchase a SIM card before departure. Nonetheless, pay-as-you-go services are generally cheaper than international plans from your local provider.
We recommend doing some research before boarding a plane. Learn about local carriers to find the best plan for your needs. Find a store located near your accommodated location—it could even be a corner store type of place. Lastly, determine what you’ll need to acquire the card as some countries will just ask to see your passport; others, like Germany, Italy, and India, will require proof of residence.