These all with one mind were continually devoting themselves to prayer (Acts 1:14)
Prayer is the foundation for all of life. Imagine the emotions and sense of fear and expectancy when Christ had been resurrected, appeared to His disciples, and then ascended. They were instructed to merely wait for the coming of the Holy Spirit who would endue them with power to be witnesses to Christ all across the world (Acts 1:8).
So, what did they do?
There was a habit that Jesus seemed to have acquired. We see it multiple places in Scripture, but it is most clearly seen in Mark 1:35:
In the early morning, while it was still dark, Jesus got up, left the house, and went away to a secluded place, and was praying there.