Java - How to remove temporal coupling?

I received from following comments on my code :

It is a procedural design, and there is temporal coupling between lines in method names().

It is quite apparent that what names() is doing—creating a list of names.

In order to avoid duplication, there is a supplementary procedure, append(), which converts an item to lowercase and adds it to the list.

 class Foo {
  public List<String> names() {
    List<String> list = new LinkedList();
    Foo.append(list, "a");
    Foo.append(list, "b");
    return list;
  }
  private static void append(
    List<String> list, String item) {
    list.add(item.toLowerCase());
  }
}

Can any one give me some pointers like how can I improve this design ?