“And it came to pass about an eight days after these sayings, he took Peter and John and James, and went up into a mountain to pray.”
Luke 9:28

The main verse shows us how deliberate Jesus was about his times of prayer, he took with him two men and went up into a mountain to pray; purposely separated himself from people, tasks and events to spend time praying, and the Bible says:
“And it came to pass, that on the next day, when they were come down from the hill, much people met him.” Luke 9:37
So he stayed there the whole day! Popular words in Christianity like “going up the mountain” started with Jesus, if he did so- being the word of God and God himself- while he walked on the earth, then we should also.
Your spiritual improvement becomes a choice, a decision you make to separate yourself from the noise of the city where you reside to spend quality time in prayer, at times alone, other times with like minded people, like Jesus did with Peter, James and John.
In such meetings, supernatural and spectacular changes would happen in you and with you that would probably not have happened while you prayed back home:
“And as he prayed, the fashion of his countenance was altered, and his raiment was white and glistering.” Luke 9:29
Purpose is accurately defined and even better, the next line of action you should consider is made clear to you, just like it was to Jesus:
“And, behold, there talked with him two men, which were Moses and Elias: Who appeared in glory, and spake of his decease which he should accomplish at Jerusalem.” Luke 9:30-31