Generally in SharePoint we do lot of work using features. We have two Xml files while creating the feature they are Feature.xml and Elements.Xml. While writing the properties in these XML files generally we will not get the Intellisense. For this we need to add the XSD Schema files on each xml files.
Here are the steps to get this
The Feature.XML without Intellisense
Open the properties of Feature.xml(or F4). And select the button beside of Schemas
Schemas window will be opened. Click Add Button. And then navigate to the wss.xsd path
“C:/Program Files/Common Files/Microsoft Shared/web server extensions/12/TEMPLATE/XML/wss.xsd”
Then you will get the Intellisense