The essential elements of the quiet time are prayer to God and meditation on Scripture and this can take a number of different forms. After talking about what it is and why it is important I thought I would give some practical advice for those who want to start or reboot their quiet time.
Pick a time, any time. While there are some exceptions to the rule, I am convinced that it works best for most people to set aside a particular time each day for private worship. Don't listen to people who argue it has to be in the morning. I personally think that is the most ideal time, but biblically one could argue we should have a quiet time morning and evening - and most are not making that argument. So pick a time: in the morning before work, at work on your lunch break, or before you go to bed in the evening. These quiet times of worship before the face of God are an essential element to your spiritual health. Consider that time sacred. Guard it. Look forward to it for what it is - you are meeting with God! If, in God's own providence, that time is taken from you on a particular day don't beat yourself up with false guilt. You can still meditate on God's word and pray throughout the day, and it is likely that you can make time later in the day to meet with God privately. Remember that while this time is very important, it is not the whole of your spiritual life. Prayer and meditation must continue throughout the day, every day.
Start small. People sometimes set good, if big, goals for themselves when beginning or restarting this discipline. Unfortunately, instead of building up to those goals they attempt to immediately master it all. Maybe you've experienced this. You plan for the one hour morning devotional: 30 minutes studying God's, maybe sing a song, 25 minutes praying - whatever. Sounds simple. But what people find is that filling an hour with concentrated discipline is harder than imagined, especially for those not in the habit of doing it. For most it is a good idea to start smaller. One's devotional life is not a competition, and we should be less interested in following another man's pattern and more interested in cultivating an authentic time of private worship with God. My advice is, if you have been disengaged in this discipline for a while, start small. Pick an epistle, commit yourself to reading one paragraph a day, write down any thoughts you have on that passage. Pray for God's blessing, provision, guidance, etc (more on prayer in a minute). This may wind up only being 10 to 15 minutes in length, but that's fine. The important thing is to get this discipline going in your life. I have found that once you start it, it is easy to cultivate it and see it grow.
Pray with helps. I have had a number of people tell me that they just don't know what to do when they pray, or that they feel like they want to spend more time with God in this particular discipline, but they do not know where to take the conversation. Like Jesus' disciples we must be taught how to pray. One of the most common prayer helps used today is the ACTS model. My prayer life is generally characterized by the elements of this approach, though I am not always conscious of the acronym. In case you are unfamiliar with this let me give you the run down. ACTS functions as an acronym; each letter of the word describes a different component of prayer.
ADORATION: Begin your time of prayer adoring God for who he is. This aspect of prayer is entirely dependent on your theology. The more you know about God the more equipped you are to spend time celebrating his character. Does the passage or biblical book you have been meditating on reflect God's holiness, justice, goodness, immutability or sovereignty? Let this frame the beginning of your conversation with God.
CONFESSION: After considering the beauty of God our own sinfulness should be apparent. Spend time examining yourself, confessing your sin to God, seeking forgiveness and begin the work of repentance. This is not the whole, but it is the beginning of the work of daily dying to our sin.
THANKSGIVING: Gratitude has been called the foundation of Christian ethics. It is certainly the appropriate response to the God who gives us all good things, justifies us in Christ, adopts us as his children, sanctifies us by his Spirit and gives us continued grace to persevere to the end. Tell God what you are thankful for. Be specific.
SUPPLICATION: Supplication is act of humbly seeking God's grace - particularly on behalf of others. This is the time when you can pray for others: for salvation, healing, provision, influence, growth, etc.
Much more needs to be said about prayer; ACTS is just a starting point. Using a method may sound mechanical and artificial to some, but let me assure you it is a great help to those who are struggling with the discipline of prayer.
Memorize one verse a week. It may not sound like much, but let's be honest - this is probably more than you are doing right now. Pick a verse from what you are/will be reading in a given week. Print it up and carry it with you. Or choose a passage and work through it one verse at a time. Keep in mind, there isn't value in simply memorizing sentences. The value of memorizing Scripture is that the Bible reveals God to us, fuels our thoughts and prayers, enables us to meditate on it anywhere/anytime, and it is what God the Holy Spirit uses to sanctify us. One of our members at Grace, Ed, began memorizing Scripture early on after his conversion. I encouraged him to take it seriously, so he printed up a chapter of Scripture at a time and taped it to the windshield of the garbage truck he drove. He memorized the whole book of Galatians. That was back in 2002. He still has it memorized and refreshes his memory about once a month. He now leads our deacon ministry.
Start a journal. This is not for everyone, but I have found it to be a very helpful part of my life. I have done it off and on since 1993 and have about 9 journals that rest behind my ugly brown reading chair that span the past 14 years. Journaling can be done in a wide variety of ways. It can be a helpful way to record what you are learning in your meditation on God's word, your prayers and how God answers, what you are learning and experiencing on a very personal level - or just about anything. Most of the time for me it has been thoughts that flow out of the passage I read that morning, and it becomes a form of preaching to myself. Journaling can be a great aid in thinking through the passage and it can prepare us to share what we are learning with other by forcing us to articulate it for ourselves first.
Mix it up. I believe routine can be very helpful in maintaining private worship, but I have also found that mixing things up is just as helpful. It is good to introduce new elements (singing, journaling or memorization as examples) into your quiet time. Variety is often good, so mix it up as you need to. Stay in the same book, but read a larger or smaller passage. Change the order through which you typically do your quiet time. Write out your prayer. Go for a walk as soon as you have finished your reading of Scripture and spend the rest of your time meditating and praying through that passage as you walk around the block. Listen to the passage of Scripture online instead of reading it. Mix things up from time to time, try something new.
These are just a few words of encouragement to those who need them. Of course there are great resources out there that are much more thorough than what I have given here. Those words are more valuable than mine so I strongly encourage you read them on this topic. Here are just a few that have really blessed me in one way or another.
Spiritual Disciplines of the Christian Life by Don Whitney Celebration of Discipline by Richard Foster Ten Questions to Diagnose Your Spiritual Health by Don Whitney The Christian's Daily Walk by Henry Scudder The Bible and the Closet by Thomas Watson and Samuel Lee The Practice of Piety by Lewis Bayly