I’m not sure of where you heard what you did, or what the speaker was specifically referring to… but…
In general, prayer has been identified as a raising of one’s mind to God…
We are supposed to turn to God in all that we do, so, if you have to make a decision, then you should be turning to God. Usually in reference to conversion of sinners, the process is called “metanoia”, which often refers to looking back to the Gospels for your answer.
I think that’s a pretty big proposition though. Knowing God’s will is a big step, and who would dare say they are that good?
The prayer process becomes one of discernment. Ultimately, we are supposed to “examination of our conscience” in order to accept the good and reject the bad. This highly orthodox process is recognized in the Catechism under the sections on prayer, and it comes from Ignatian thought.
Father Timothy Gallagher has an interpretive lecture series in video format of Saint Ignatius’ Spiritual Exercises, some of which can be found here:
catholictv.com/Father-Tim-Gallagher.aspx
Although this is not the complete series, like it used to be, it does have the first few episodes concerning decision making. You may have to search around for the complete series, if you want to know more. Also, Fr Gallagher refers to “The Fourteen Rules”, which I have attached for you on this post.
I’ve been studying this for several years now. Some people dont like St Ignatius, as they think he was radical, but the Catechism is full of references to him.
If I were in your position, which I am, then - when I make any decision - I use the Rules and Scripture to serve the greater glory of God. That’s why we were born; that’s our purpose in life.
And, if I fail, then I go to confession. This gives God the glory, for we all fall at some point. But - where sin abounds - grace abounds all the more.