First of all, write your name and address in the upper left-hand corner of the envelope. Then write the name and address of the person you are mailing the letter to in the center of the envelope. This usually takes three lines. Put the name on the first line. Write the street address on the second line and the city and state on the third line. Remember to include the zip code. Finally, put a stemp in the upper right-hand corner. The most important thing to remember is to write neatly!