In our store, there are two types of product.
One is "Free Shipping", another is "NOT Free Shipping"
If you have two types of item in the shopping cart, you can save shipping fee by spliting the orders.
Here is how:
1. Checkout all your FREE Shipping items first, then choose "FREE Shipping" as the shipping method and paid it.
2. Checkout all your NON FREE Shipping items in the 2nd order, and choose the shipping method you like.
For most of the case, you will save the shipping fee.
The reason is, your first order is using FREE Shipping method, and the 2nd order is using the one you choose, say DHL.
However, if you want to get BOTH your order by DHL (or any other specific method), you should NOT split your order.
As free shipping item DO NOT included DHL shipping fee.