Standard example: @models = Model.all select_tag "models", options_from_collection_for_select(@models, "id", "name"), {}
This will generate the following HTML: David
The last argument are options, which accepts the following: { multiple: false, disabled: false, include_blank: false, prompt: false }
More examples can be found: http://apidock.com/rails/ActionView/Helpers/FormTagHelper/select_tag