So McCall argues that 'white magic' is, or ought to be, one aimed-at goal in these times. Indeed, I cannot think of any more-valuable and more deeply-satisfying thing someone can do than this.
Valuable because it is a contribution to God's ongoing work of creation; satisfying because that which we contribute is from our unique individuality (exactly which, nobody-else could contribute).
But how to do it? It is clear that good magic ("white magic") cannot nowadays be done as it was in the past. The modern consciousness has become almost completely cut-off from the divine if there is reliance upon spontaneous and unconscious mechanisms. Also cut-off from the consciousness of other-Men for old methods of aligning our will with the divine. So modern Man experiences himself as alone in a meaningless universe.
To regain and experience 'participation' in both consciousness and that of other Men; Modern Man needs to attain this in a conscious and chosen fashion, in thinking (i.e. the state of Owen Barfield's Final Participation).
If this is the "Magic" we need to seek; the how do we seek it? Given that any attempt to compel Magic by will-power can only be ineffective, or lead to 'black' magic.
Well, first of all we need to be able to 'detect' Magic when it is happening - and when it is not. We need to learn that discernment in ourselves. Simply by knowing and valuing Magic, we will tend to increase its intensity, duration and frequency - as contrasted with someone who does not value Magic who will be more likely to think or do something that dissipates the state.
Then we can learn in a negative sense what states of mind and conditions are hostile to magic. For most of us that will be situations of distraction, hyper-stimulation, rigidly constrained circumstances (like bureaucracy and form-filling), and passive states of impaired consciousness (including intoxication).
In general, modern Man tends to seek passive forms of consciousness; seeks to be overwhelmed by external stimuli (such as media inputs; novel or highly-stimulating situations) - but if attained, this blocks any possibility of White Magic.
Eventually we might learn the kind of activity and situation that is conducive to the sought-after Magical consciousness. McCall mentions art, prayer and meditation - and of course these terms are very broad in themselves. But also there are particular places, 'hobbies', activities (such as walking) - even certain times of day.
Circumstances will never be causal, but may be conducive - yet even what is conducive will change through time due (for example) to habituation, changing specific situations, and changes in personality - including illness.
Therefore what helps in attaining the Final Participation state of Magic needs to be discovered for each person; and probably rediscovered as what once worked well, loses its effectiveness.
This is a world where all political activity in opposition to the Satanic Global Establishment is increasingly illegal or impossible. We can interpret this as a further encouragement to do what we, anyway, ought to be doing - which is to stop seeking political Answers to the evil of these times; and instead to focus on a Romantic and Christian response of purposive, individual, spiritual activity.