Keep your return and delivery address separate to minimize any confusion. Your delivery address should be centered, and your return address should be separate in the top left corner. Avoid any merging between the return and delivery address. Just in case your delivery and return address are placed too close to each other, writing sender over your return address will eliminate any confusion. Add a colon mark after the "SENDER" and continue adding your address below it. Begin with your street address, apartment or suite number, and/or directions on the first line. Follow your street address with your city and zip code. While both your delivery and return address should be written clearly, the legibility of your return address is particularly important. If for whatever reason your package cannot be delivered, it will be returned to the sender. Place a white label over your package's address and re-write the return address if it is smudged or sloppy.

TL;DR in Chinese:
在包裹的左上角填写退件地址信息。 在“寄件人”一栏填写你的地址信息。 寄件人地址格式和收件人地址格式一样的。 复查字迹，看看是否清晰。