Within the Product Features link you can add product features (either shared or private) to the product you are editing. You have the option of creating a private feature here, which will only apply to this product or adding a shared feature (which can be applied to several products and is created outside of the product). Simply decide which type of feature you would like added (private or shared) and then select from the drop down menu which type you would like to add. Once you have selected the feature from the drop down menu click the Add or New button.
Add Shared Features: click on the drop down menu or small down arrow to view list of shared features. Once you have chosen which shared feature you would like to add click on the word so that it becomes highlighted. Once it is highlighted click the Add button to add it to this product.
Add New Private Features: Private Features will only be added to this product. When adding a new private feature to a product you must first select which type of feature you would like to add, choose from Text Input, Drop Down List, Radio Button List, HTML Area, Accessory Checkboxes, Accessory Drop Down List, Accessory Radio Button List. Once you have decided which type of feature click on the name so that it becomes highlighted and then click the new button. Below find the type of feature you have chosen and follow the instructions provided.
For explanations of each type of product feature visit Shared Features.