When setting up free shipping on AliExpress, the following aspects should be considered:

1. **Logistics cost calculation**: First, you need to understand and calculate the freight quotes of various logistics channels. Taking China Post Registered Parcel and e-mail as examples, merchants can download the corresponding freight quotes from the AliExpress backend and organize them into a table. According to the weight of the goods, use tools such as EXCEL to calculate the freight for each country.

2. **Set free shipping countries**: According to the weight of the goods and logistics costs, set which countries can enjoy free shipping services. For example, if the shipping cost of a 60g product to the United States via e-mail is 18.96 yuan, then the United States can be set as a free shipping country.

3. **Calculate the postage of other countries**: In addition to the free shipping countries, you can set a calculation formula for the postage of other countries. For example, subtract a certain amount from the postage of the free shipping country. If the calculated postage is a negative number, you can consider that the country also enjoys free shipping services.

4. **Product cost consideration**: The pricing of free shipping service also needs to consider the cost price of the product. Some merchants will choose to add a certain amount of money to the product cost price as postage, which also depends on the merchant's profit requirements and market competition.

5. **Buyer choice consideration**: The AliExpress platform allows buyers to choose different logistics services. If the buyer chooses a logistics method other than free shipping service, the merchant needs to set a reasonable additional fee to ensure its own profit.