The real way to develop a mind that clings to nothing is to first, continue to let go. Moment after moment, notice the clinging and then let go. Over and over again.
And then to expand yourself beyond your narrow perspective, to see the interconnectedness of all things, to appreciate the beauty in all around us, to not see yourself as separate from everything else but a part of it all, in it together, and fall deeply in love with that fact.