Asking this is like saying how can I feel sadness, how can I feel hapiness, how can I cry, how can I move my arm, how can I turn my eye. All is in the natural instinct of the brain. If you can't enter this state, you don't understand the music nor it's point. Too, playing too easy pieces is boring enough, and it's hard to enter this state with some easy pieces. Try hard intense pieces to get the first feeling. When you'll know what the feeling is, you will be able to feel it in non-intense works, but that are beautiful. Don't try to get this feeling by playing Bach's menuet in G.