It seems that, not often than not, the practice is a matter of balancing one’s perceptions. I have be seen white heavily focused on the brahma viharas and hand been struggling with over indulgence in sense pleasures. Having been down this road a number of times before I realized just this morning, after having been assailed by kilesas for a week, that it might be a good idea to bring the perceptions of sickness, aging and death to mind.
Naturally they aren’t a magic charm but each time a thought of sense pleasure arose I would reflect on these perceptions to god effect. Until liberation may we never become enslaved to that which sickens, ages and dies.