If you had to create a Mind Diet, what to put in your mind and what to discard, what would that diet consist of and how would you go about sticking to the diet?
" 'Guarding the sensory faculties' means protecting your mind against such attachment and hostility, and making great effort not to produce them." -Je Tsongkhapa
My Mind Diet would be setting the mind on only Virtuous Objects and steering my mind away from Non-Virtuous Objects. This means I'd study and contemplate Virtuous Objects--impermanence, love, emptiness, ethical discipline, karma, etc--and set my mind single-pointedly on those strong feelings that come from such contemplation. I'd alternate between analysis and single-pointed focus on these Virtuous Objects in meditation, and when not in meditation I'd study and contemplate them.
I'd also cultivate as much concentration as I could and try to work my way through the 10 Levels of Calm Abiding to strengthen my ability to steer my mind away from Non-Virtuous Objects and set it on Virtuous Objects when not meditating and also to keep a strong, clear, and relaxed single-pointed focus on the feelings that arise from analysis of Virtuous Objects during meditation.
When my wife watches sources of Non-Virtuous Objects such as The Real Housewives, I'll steer my mind away from those objects and practice Tonglen or will read a Dharma book while sitting next to her or put on the headphones and listen to a book by His Holiness the Dalai Lama.
Over time, my mind would mix with Virtue and bring about great happiness in daily life while diminishing the afflictions of attachment, hatred, and ignorance caused by focusing on Non-Virtuous Objects in my mind stream. I'd particularly focus on 3 Antidotes to the 3 Poisons of attachment, hatred, and ignorance: Impermanence, Love, and Emptiness.