I spoke about these supports for developing concentration at the day-long last weekend. For those of you who asked for the written list, here it is. You can find more details on this list in the Visuddhimagga or in my book Wisdom Wide and Deep.
“Eleven supports for developing concentration: (1) Cultivate cleanliness; (2) Avoid extremes; (3) Choose a clear subject for meditation and know your object well; (4) Dispel sluggishness; (5) Calm the mind when it becomes overenthusiastic; (6) Encourage the mind when progress is painful or slow; (7) Maintain a continuously balanced awareness; (8-9) Avoid distracted friends and seek the company of focused friends; (10) Reflect on the peace of absorption; (11) Incline the mind to develop concentration.”
—Shaila Catherine. Wisdom Wide and Deep, page 55-59