I have a select that uses ng-options to populate the select as follows:
Just add a default option, just so angular will use this option when there is nothing selected in the ngModel or an invalid item is populated in the model. This way you don't need to add an empty value in your collection.
<select class="form-control"
ng-model="Data.selectedPerson"
ng-options="v as v.Name for v in Data.people track by v.Name">
<!-- Add your default option here -->
<option value="">Please select a person</option>
</select>
You could also change the text based on the condition:-
<option value="">{{ Data.people.length ? "Please select a person" : "No one available for selection" }}</option>
You can also remove it from DOM if it has already a selected value.
<option ng-if="!Data.selectedPerson" value="">Please select a person</option>