Custom Object:
<types>
<members>*</members> // * will return all object and custom settings
<name>CustomObject</name>
</types>
Custom Field:
<types>
<members>Account.AccountSource</members> // Should specify object field names.
<name>CustomField</name>
</types>
Apex Class:
<types>
<members>*</members>
<name>ApexClass</name>
</types>
Apex Component:
<types>
<members>*</members>
<name>ApexComponent</name>
</types>
Apex Page:
<types>
<members>*</members>
<name>ApexPage</name>
</types>
Apex Trigger:
<types>
<members>*</members>
<name>ApexTrigger</name>
</types>
Page Layout:
<types>
<members>*</members> OR <members>Account-AccountLayout</members> // To retrieve all layout from org use “*”. To retrieve specific layout use Object API and “-” and Layout name.
<name>Layout</name>
</types>
Record Type:
<types>
<members>*</members>
<name>ReportType</name>
</types>
Custom Buttons:
<types>
<members>ObjectName.Button name</members> // Not button label name
<name>WebLink</name>
</types>
Custom Label: //To pull specific custom label
<types>
<members>Label Name</members>
<name>CustomLabel</name>
</types>
Custom Label: //To pull all custom label from org
<types>
<members>*</members>
<name>CustomLabels</name>
</types>
Will be adding more later………..