I found it helpful in terms of those times when we stop our practice of prayer
Prayer, in the sense of union with God, is the most crucifying thing there is. One must do it for God’s sake; but one will not get any satisfaction out of it, in the sense of feeling “I am good at prayer. I have an infallible method.” That would be disastrous, since what we want to learn is precisely our own weakness, powerlessness, unworthiness. Nor ought one to expect a sense of the reality of the supernatural of which I speak.
And one should wish for no prayer except precisely the prayer that God gives us
– probably very distracted and unsatisfactory in every way.
On the other hand the only way to pray is to pray. And the only way to pray well is to pray much.
If one has no time for this, then one must at least pray regularly. But the less one prays, the worse it goes. And if circumstances do not permit even regularity, then one must put up with the fact that when one does try to pray, one can’t pray – and our prayer will probably consist of telling this to God.
As to beginning afresh, or where you left off, I don’t think you have any choice. You simply have to begin wherever you find yourself. Make any acts you want to make and feel ought to make, but do not force yourself into feelings of any kind.
You say very naturally that you do not know what to do if you have a quarter of an hour alone. Yet I suspect the only thing to do is to shut out everything and just give yourself to God and beg for God’s mercy and offer God all your distractions. (Dom John Chapman in Martin Laird's Into the Silent Land)