It’s amazing what kids can absorb about gratitude when they learn by example.
Give Beyond Your Friends and Family.
When giving gifts (such as Chanukah or mishloach manos or anytime throughout the year) to teachers, friends, and family, remember the people like the plumber, the store clerks, the handyman, and the neighbor whose kitchen you frequently shop in. People who you rarely remember until you call on them will really appreciate being remembered, and your kids will learn gratitude by watching you.
Make a Family Program
Give your kids incentive to notice what others did for them and express their gratitude. Ari held the door for me on the way out to carpool; Thank you Yaffa for offering me the last cookie! For each action they want to thank someone else for, they may put a popcorn kernel in a baby food jar. When it fills up, make a popcorn party or some other fun activity to reward everyone for their actions and for thanking each other.
Express It in Writing
Leave notes under the challah cover for your husband, thanking him for things he did from Shabbos to Shabbos (I heard this one from Mrs. Bonnie Cohen of Yerushalayim).
Give Your Kids a Pekelech of Notes
Give personalized pekelach of tiny papers filled with thank you notes to your kids in tiny cinch bags for Shabbos. These bags come in so many colors you can get a designated color for each child. Do them even for those who cannot read; they will love to hear them read to them over and over.
Say It Out Loud
Notice Hashem’s kindness in foods (fruits are especially easy) and show the kids: the star that shows up in an apple when you cut it in half, the skin that protects, the attractive colors, etc.
Say Thank You
Thank Hashem out loud, in front of your kids. Do this by making clear blessings out loud. Also thank Hashem in your own everyday language, aloud. Let your kids hear you. (… “see how Hashem made your teeth fall out only one at a time?What a chesed! Your skin grew back to cover your papercut? Amazing! Thank you, Hashem for guiding my footsteps today so that at exactly the most helpful time I met into…or, Hashem, thank You for the rain, and thanks for holding it until just after I brought in all the groceries…)
Look for the Best
Privately think of a challenge that you are going through, and thank Hashem for something sweet inside that challenge. Do this daily and it will become a part of you. Whatever is a part of you (hopefully just the good stuff) affects your kids even without a conscious effort to give it to them.
Play a Game
Play The Gratitude Game (at the supper table, or at the Shabbos meal) and keep a running list of things you have never thanked Hashem for before! Have you ever thanked Hashem for gravity? Isn’t it sweet Hashem gave us the experience of gravity so that every time your learning-to-walk toddler falls, you don’t have to peel him off the ceiling? (Thank you Rabbi Z. Pliskin for this image.)