Force.com package xml

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………..