Order based shipping is calculated using Geo-Zones. You must set up at least one Geo Zone to use order based shipping.
To edit order based shipping, navigate to Settings -> Shipping and then click the "Edit" link next to Order Based Shipping.
To enter your shipping rates, you will use the format order total:cost using a comma as a separator. for example:
In this example (suppose the currency is USD), if the order totals less than $10, $1 will be charged for shipping. $10 to $30 orders will be charged $2, $30 to $100 will be charged $5, $100 to $2500 will be charged $12. Note that any orders over $2500 do not have a shipping price entered, thus would not qualify for order based shipping. If you would like to use order based shipping for all orders, be sure to include a very high upper order bracket.