When on the phone, try not to tie up the line for long periods. Alternatively, some countries have public phone centers where you can place a call and pay for it when you are done. To receive calls from the US, make sure that the people that might call you have the correct country and city code for your location. Make sure to consult with your host family or roommates to make sure the time you chose is alright with them as well. Letters Don't forget about letters as a means of communication.
Letters are cheaper than phone calls, they tend to be more personal, and can make great keepsakes.
Postcards are easy to write and can quickly be done while absorbing your surroundings at a park or caf , or on a train or in plaza. The drawback of course is that mail is slow and unreliable. If you do decide to use the mail system in your host country, never send money or valuables and avoid receiving packages. International express services can be very expensive and are not overnight. Availability will depend upon your location, but in general, expect limited access and delayed responses.