Contract Models, also known as contract deal terms, act as templates so that you can quickly add new contracts. You can use a contract model for one or more contracts.
You can find Models in the Catalog section on the left menu. Make sure to fill in a contract model reference and then name the page. The reference is used with importer templates to assign models to contracts. It is advised to use a name indicating the percentage at hand, such as "Default 80%" or "Product configuration 60%, default 80%". It is easy to spot the different deals in the UI, your importer sheets, and exports.
Once this is set, use the default percentage window to set the deal term and the calculation base (net royalty, gross royalty, or other). To further customize your percentages, you can add additional terms, such as Territory and Type of sale.