If you are not prone to write lengthy epistles, a convenient and relatively inexpensive item to use is an aerogram. Package service rates vary enormously, as does the time in transit. Avoid having important packages sent to you. In some countries there is no guarantee that they will reach you, and customs duties may be high. At some point you will probably want to send items home.
Regulations vary widely, so check first.
As a rule, do not seal your packages before taking them to the post office. The clerk will probably want to see what is inside. You are cautioned against misrepresenting what may be contained in a package. U.S. Customs opens packages regularly and randomly. Making a false declaration or sending illegal items home can be a serious matter.