Becoming a magical adept is the goal of any legitimate initiatory path in the Craft. The bulk of the good schools of the Art do not cater to self-study, but to membership.
Finding a workable self-study initiatory path can be challenging. There are a few, and many of those are riddled with magical "blinds." These blinds are concepts or practices which have intentionally been presented incorrectly, and only those "in the know" would be able to see.
These blinds either severely limit or completely abolish the effectiveness of the magic when not corrected.
The Psalms don't have any blinds; well, that is unless you call having them included in the Bible a blind. Most people looking for magic wouldn't really think to look there.
As far as effectiveness goes, as long as you are practicing the Psalm Magic Formula, you are persistent in your practice, and you are only working magic on things that are in your Magical Sphere of Influence, you will see amazing results no matter what.
But beyond practical magic, the Book of Psalms is an entire initiatory path. That's right. The Book of Psalms can make you an adept. Here's how the path works:
You work each 150 of the Psalms in the Book of Psalms, using the Magic Psalm Formula. Each round through the entire book is a single degree of initiation.
Rushing through the Psalms does not count. You must take a MINIMUM of one day per Psalm, and spending multiple days on any Psalms which call to you to do so.
Doing the Psalms in order is not necessary. Just keep a list of Psalms and check each one off after you have completed working it.
Having a goal of finishing a Psalmic degree in 150 days is not a wise goal.
Give yourself six months to a year to do it. This means that you are actually planting divine seeds in your deep mind, and not just chattering off incantations like a parrot.
Each time you get through the book you will notice your power has increased exponentially since the last degree. The Psalmic path is closed to NO ONE for any reason whatsoever.