I found this very helpful and practical thought in the September 6 reading of Joy and Strength, compiled by Mary Tileston:

Bringing into captivity every thought to the obedience of Christ. 2 Corinthians 10:5

Some have found it a useful thing when their minds have wandered off from devotion and been snared by some good but irrelevant consideration, not to cast away the offending thought as the eyes are again lifted to the Divine Face, but to take it captive, carry it into the presence of God and weave it into a prayer before putting it aside and resuming the original topic. This is to lead captivity captive.
~ Charles Brent