The breath prayer -- one way to follow the practice of praying without ceasing -- is also a way I've maintained some semblance of sanity and faith in the bad times. It's so simple, but so profound.
The first person who actually suggested developing a breath prayer to me was a Hindu. He called it a mantrum. It worked so beautifully for me that I was pleased to later find out that it is an ancient Christian tradition as well. It is basically a short prayer sentence that you mentally recite as you breathe in and out.
It's so easy to do. You pick out a short prayer, and soon using it in your daily life becomes pretty natural and routine. When I wake up at night, the breath prayer is the first thing that comes to mind.
Perhaps the most famous version is the Jesus prayer, which can be traced back to the sixth century: Lord Jesus Christ, have mercy.
Some people feel that you can "discover" your own breath prayer by ... amazingly enough ... getting quiet and praying about it. Others develop their prayer by imagining a conversation with God, asking for what they really want, and combining that request with their favorite name for God (as in "Jesus give me peace" or "Father show me your love.") You can create a breath prayer out of a favorite piece of Scripture, or just pick a classic like "Come, Lord Jesus."
My breath prayer is "Come, Holy Spirit," which invites the Holy Spirit to control my mind (such as it is these days.) It's four syllables, and I think it would be tough to go beyond six to eight.
Once you've picked it, practice it. Say it as you breathe while you are walking or waiting in line. Try it when you are agitated and when you are enjoying the beauty of nature. And say it as you are going to sleep, after you've figured out five things you are grateful for. It is truly restorative. A breath of fresh air, no less.