I think with long devotionals of pray we can just know when we can ask and receive. There are times when it is not like an "On" button but then you will just know it. It can just happen when it happens.
Devotional Moments with the Lord are more time spent in His Presence whether we feel it or not at times. The more we spend the more the Holy Spirit will open up layers of unseen wisdom in the Scriptures whether During Mass or Regular reading or Audio Bible.
My mother could pray until things were taken care in the Family. My Father had a stroke . The doctor told my mother he would never work again . My mother just looked at him declared are you in the office of God now. She then told the doctor He has to get well.
"He is the bread winner"
Then declared without a doubt he will be well. A mother of 7 standing on what she knew from long hours of pray. My father was healed went back to work in a month or two(I was young). He retired with a pension.
He will help our needs not our greeds.
My mother prayed some amazing results at many times. It is not to be flaunted the wrong way either.
I can know at times. It is not always but if I do it is always after beautiful time of pray I can see through the eyes of faith.
God is so Good!!
Praise Jesus!!