I like all of this except "think of nothing", this is not possible for humans! How about "let thoughts slip away, don't linger". On "no guided audio or apps".... there are different schools of thought. I think starting with an app with an aspiration of being unguided can be good approach. Of course the ancients didn't have apps, so I appreciate where you are coming from, but i would hate for people to start there on their own and then bail....