"A noisy bus isn't often the best place for classic meditations, but we can start on some things."
She explains controlled breathing exercises and an initial posture to take. (One with much less slouching. Feet on the floor, spine straight, chin up, hands on thighs...)
"Work on establishing an even rhythm first. Over time, you'll want to slow your rate down - but you need to be able to control that rate, first." (The pattern she recommends - breathe in, hold, breathe out, hold. She wants the Keres to try three seconds in, three seconds hold, four seconds out, and two seconds hold first, and increase each of those numbers until she feels she's pushing herself - and exhale time should be increased fastest, the hold times slowest. The point is control, not holding her breath.)