There are a few ways to set up shopify rates in shopify
1) Set shipping rates based off of the weight of the product. However, when using the ''Weight based'' option, it's important to bear in mind that we are using different carriers for different products, and that the consolidated shipping price of the products is not unique and cannot be precisely calculated only by product weight. Additionally, we consolidate the price per box that the items are shipped in, and not per weight of the items themselves.
2)Set shipping rates based off of the price of the product. Shopify allows you to set the shipping price based on the price of the product. For example if you sell T-shirts for $20 and Mugs for $15, you will be able to set shipping prices per price of the product
3) Offer free shipping to all of your customers and include the shipping cost in the cost of the product. That way you don't have to worry about losing money since your customers will always pay for the shipping per item, and we will charge you the consolidated price. And on the plus side, your customers will think you're giving them free shipping :)