There is simple way to add space between controls( buttons, text boxes..etc..) in an linear layout. Add the following attribute in the controls,
<Button
android:layout_width="280dp"
android:layout_height="40dp"
android:layout_marginTop="15dp"
/>
This will allow 15dp space above the button. Likewise you can give space between each controls. You can use the following attributes too,
android:layout_marginBottom="10dp"
android:layout_marginLeft="10dp"
android:layout_marginRight="10dp"
android:layout_marginStart="10dp"
android:layout_marginEnd="10dp"
