Jesus was a good Jew, and like all good Jews he prayed multiple times a day. In the ancient world, Jews prayed two times a day (morning and evening prayers), or in some times and places (like first century Jerusalem), three times a day (morning, noon and evening). These regular prayers consisted of:
1. The Shema
"The Lord is our Lord, the Lord is one. You shall love the Lord your God with all your heart, with all your mind and with all your strength." (Based on Deuteronomy 6:4-5)
2. Some version of the Eighteen Benedictions
Jesus later replaced the 18 Benedictions with the related, but more compact, gospel-oriented Lord's Prayer:
"Father, hallowed be Your name. Your kingdom come. Give us each day our daily bread. And forgive us our sins, For we ourselves also forgive everyone who is indebted to us. And lead us not into temptation.'"
3. Daily requests
Probably done during a main time of prayer, either the evening or noon prayer.
These prayers could be done by oneself or with others in a synagogue.
1. Brief prayer
Jesus taught that prayer did not need to be long, especially since long prayers often call attention to oneself. (Matt. 6:7-8)
2. Direct prayers
Jesus taught not to elongate or to have unnecessarily repetitious prayer. Of course, the Lord's Prayer is a repeated prayer, but Jesus isn't speaking against liturgy, here, but against repeating the same words over and over. "God already knows," Jesus says, "saying it once is sufficient to make the request." (Matt 6:7-8)
3. Secret prayer
Jesus commanded prayer in secret. This did not mean that all prayer should be private, as the Lord's prayer and many prayers Jesus spoke were public. But Jesus warned against all prayers being public, because prayer could be a display for others in that circumstance, and not actual speech to God. (A good warning for religious leaders.) (Matthew 6:6)
4. Public prayer
Jesus commanded some public prayer, such as the Lord's prayer which implies it to be done with others ("Our Father"; "give us our daily bread").
5. Spoken prayer
All the prayers we have of Jesus were spoken aloud. Even Jesus' most private prayer "Take this cup from me" was spoken aloud. (Matt. 11:25; Mark 14:36)
Although it is not significant, the only physical position Jesus' mentions for prayer is standing. (Matt. 6:5; Luke 18:11, 13). The only position mentioned for Jesus was on the ground (Mark 14:35), although this seems an exception.
1. Communion with the Father
Jesus sought to spend time with God the Father as often, as he could. During his regular ministry, it was difficult to get time alone with God, so he would occasionally get up before everyone else to pray, or send everyone away in order to have an hour with God. His life was so busy that it wasn't always possible, and his communion time was often cut short. (Mark 1:35; Mark 6:45-46)
Of course, Jesus spent one time in fasting and prayer for 40 days before his ministry. In this time, it seems that he didn't eat for the full period of time, but he did drink water. (Luke 4:1-4)
It was a common Jewish practice to spend one day a week (Friday) in fasting since the time of the Babylonian exile. It seems that Jesus did not participate in this fast, but he suggested that his followers would participate in this practice after he was no longer with them (Luke 5:33-35). Jesus expected his disciples to fast, which is why he gave instructions for them not to display their fasting practice to others (Matthew 6:16-18).
3. All night prayer
There were two nights in which Jesus prayed all night. Once when he was making the decision as to who would be the 12 apostles. The second on the night before his arrest and death. The first seems to be a time in which Jesus needed the Father's direct guidance. The second, as Jesus told his three closest disciples, was in order to be prepared for the time of trial that was to come. (Luke 6:12-13; Mark 14:32-42)
4. Declarative prayer
On occasion, Jesus would just proclaim an impromptu praise, or a public prayer for others. Jesus would also use portions of the Lord's prayer as the basis for prayer in his own words. Jesus' prayer was sometimes based on liturgy and sometimes completely spontaneous. (Matthew 11:25-26; John 17)
All kinds of Christian practice come from this pattern of prayer. However, there is little that we can use here to condemn others. The only practices Jesus actually commanded is the use of the Lord's prayer and the practice of isolated prayer. Apart from that, there is much freedom for all Christian practice of prayer, including spontaneous prayer and liturgical prayer; forty days of fasting and no fasting; all night prayer and brief prayer. Like Jesus, it might be good that our prayer practices vary and depend on the circumstance.