Swami Sivananda:
There is no use of praying to the Lord by fits and starts or every now and then. Do Japa and meditation regularly without any break even for a single day. Just as you do not give up tea and meals even for a single day, and just as you do no forget them too, so also, do not forget Sadhana– whatever little you can and then only take your meals. This is a sure and potent way of goading and compelling the mind to penetrate itself deeply and unavoidably into the spiritual practices. By following this procedure, you get used to doing Sadhana regularly at least for the sake of the meals that is necessarily to succeed, in spite of the unwillingness of the mind.
When the mind undergoes phases of transition in enjoying the charm of the world, it cannot concentrate upon itself and direct the gaze within itself. Pull the reins of the mind back towards itself as it goes out hither and thither. Continue this process several times in a day. When you develop strength of will to realize the Lord by intense efforts, progress automatically sets in. Read the Second Chapter of the Gita with meaning. You will have a clear understanding of the remedy for setbacks in Sadhana.