We have been using this technique all the time, throughout our practice. Particularly in Dharmic
environments, whenever we have a wall we post the slogans in order to remind ourselves of them.
The point is to catch the first thought... The idea is that in catching the first thought, that first thought should have some words.
In this case, whenever you feel that quality of me-ness, whenever you feel "I" - and maybe "am" as well - then you should think of these two sayings:
 May I receive all evils; may my virtues go to others.
 Profit and victory to others; loss and defeat to myself.
It takes quite a lot of effort because it is a big job. That is why it is called the Mahayana [big vehicle], it is a big deal. You cannot fall asleep when you are driving on this big highway...
From Training the Mind & Cultivating Loving-Kindness by Chogyam Trungpa , copyright 1993 by Diana Mukpo.
(Official Chogyam Trungpa Website)
Published by arrangement with Shambhala Publications, Inc., Boston.
This site provides an on-line database of commentaries on the Tibetan Buddhist meditation practices of lojong (Mind Training) and tonglen.