These gathas (short poems) bring me back to the moment and remind me that there is more to this world than worries, problems, opinions, desires, assumptions, and expectations. I have them available in a document on my smart-phone so that I can read through those that I don't have memorized when I need them. 
 
 
1) Waking Gatha *
    Waking up this morning, I smile.
    24 brand new hours are before me.
    I vow to live fully in each moment
    and look at all beings with eyes of compassion.
 
2) Evening Message 
I like to recite this just before zazen. I also have it printed out as a little sign, taped to my computer monitor.
 
    I beg to urge you, everyone;
    life-and-death is a grave matter,
    all things pass quickly away,
    each of you must be completely alert;
    never neglectful, never indulgent.
  
3) Meal Gathas  What initially started out as a quest to find some sort of gatha to remind me not to overeat has developed into the following meal gathas that I put together (mostly from lines that I liked from other gathas I found in various books and web-sites). In Present Moment, Wonderful Moment, Thich Nhat Hanh recommends writing your own gathas to help with whatever issues you might want to address in your own life and practice.
  
Before Meal Gatha
    For the sake of enlightenment I now receive this food,
    with gratitude to all who helped provide it
    and with solemn appreciation for the life
    that was sacrificed for my nourishment.
    As medicine cures illness,
    I take only what I need to sustain my health
    and I waste none of what I take.
    I see clearly the presence of the entire universe
    supporting my existence.
  
    In accepting this meal
    I vow to abstain from all evil
    To cultivate only good
    and benefit all sentient beings.***  
 
Then, I often include another example of Buddhist "plagiarism" (again, partly compiled from lines from other gathas) as follows:
  
While Eating Gatha
Seeing the food; it reveals my connection with the Earth and  
    the Sun.
Smelling the food; I think of those who are hungry or lonely.
Picking up the food in small bites, I vow to practice patience.
Placing it in my mouth; I vow not to speak that which will harm 
    others.
Tasting it; I offer this meal of three virtues and six tastes to the
    Buddha, the Dharma, and the Sangha.
Chewing it thoroughly and without hurry, I vow to practice
    mindfulness.
Swallowing it; I vow to offer joy to others and relieve their 
    suffering.
Drinking; I vow to wash away my delusion and character 
    flaws.
Finishing when nourished and not full; I vow to avoid 
    compulsion and greed. 
 
After Meal Gatha  
    The meal is finished
    I wish that all beings
    may accomplish their tasks
    and attain Buddhahood***
 
Note: I don't necessarily recite each one at every meal, nor do I always recite them out loud (especially in public). However, the use of gathas is a wonderful little addition to Zen practice that takes almost no time during our busy day and points us repeatedly toward smiles and enlightenment.
  
See the following sources for additional gathas:
- 
Present Moment, Wonderful Moment, by Thich Nhat Hanh
 - 
The Dragon Who Never Sleeps, by Robert Aitken
 - 
Google "gathas" for many more source
 
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*Waking Gatha from Present Moment, Wonderful Moment, by Thich Nhat Hanh 
 **Robert  Aitken's book, Taking the Path of Zen, refers to "the evening message  of sesshin, called out by a senior member of the assembly just before  lights-out."
***Before Eating Gatha and After Meal Gatha from DZC Liturgy (derived from the Flower Garland Sutra)