The second method is to offer
flat rates for all products regardless of weight and dimensions. In this case, you define the
shipping fee, which allows you to ship products with no risk of losing money. Flat rates have some perks: one can see the final shipping cost right away and save money when buying larger items.
Alternatively, offer discounts depending on the order value. Charge $5 to deliver the first item and $2.50 for every additional one. You can put all of them in the same package, which barely impacts your shipping expenses but motivates customers to increase their order value.