Classic old-time 20 min Silent Meditation:
1 - Sit alone quietly, eyes closed, wait a moment . . . then
2 - Silently repeat a short mantra(mono-syllabic is Okay) or prayer-mantra.
3 - Repeat step #2 for 20 minutes*.
4 - At finish, direct attention to any points of discomfort in the body. End.
*During step #2-3, the mind will wander away from the task of the mantra repeatition. When that happens, simple return to repeating the mantra.