There is no question about the importance and value a daily time spent with the Lord in prayer and the study of his word. I believe this is one of the most critical keys to almost every part of life. A daily quiet time is an incredible source of wisdom, strength, encouragement, direction, and on and on.
So it makes sense that every believer should excel in this daily discipline. But for most of us, our desire to excel with these devotions far exceeds our knowledge of how to do so. And there are few places to turn for help. Most contemporary books about devotional life are either very shallow or point people away from a biblical model for devotions and more toward some eastern mystical experience.
I have read a ton of books on this subject over the years, and I keep coming back to one book. The Inner Chamber by Andrew Murray is by far the best book on the subject I have read and one of the best books I have read period. It has thirty-six short chapters. These chapters are brief enough that it is easy to read one chapter a day right after your Bible reading time. Each chapter explains either one value/benefit of being committed to a daily devotion or challenges the reader with one way to make the time spent more impactful.
If you will read one short chapter a day, you will be challenged and changed in fundamental ways before you reach the end of the book. You will have a greater appreciation of what the Lord is trying to do in you during your devotions and you will know better how to allow that to happen.
No exaggeration, this is a book you will want to read once a year.