Shikantaza is the simplest, in a way the most elegant Zen practice. It means simply sitting. Thoughts arise in the Mind, you notice them, and they float away, like clouds. You return to just sitting. That’s it. The essential manifests. Shikantaza is living proof. Just here.
Note:
I have found the practice is strengthened by sitting on a pillow with you spine straight, your hands clasped in a half lotus posture, and your eyes either closed or partially open. Many practitioners of shikantaza find it useful simply to observe breathe tides, flowing in and out.