It's easy for children to get lost in the feeling of wanting everything they see.  They get wrapped up in new and exciting moments! However, this can sometimes turn into children developing a sense of entitlement.  Instilling appreciation is an important characteristic to develop in young children.  It benefits their perception of the world and makes them more joyful of the things they do have. Here are some ways that you can integrate gratitude into you and your child's lives.  
It's important to remember that children are not going to change overnight. It takes some time to develop gratitude when you're young! Additionally, it's ok for you to say no to your child when they persistently ask for cookies in the grocery store or the newest toy at the store.  If your child gets everything they wish for, then nothing seems special.  Keep the "yes" for something you know is actually important to them.  This way, the things they do get are all the more special.

Have your children help you around the house.  Start them small with things such as clearing the table or throwing away any trash from the living room.  Gradually work them up so that they are contributing members of the household.  This increases their appreciation of all that you do as a parent, but also the value of hard work.  All good things come from exerting effort.  The sooner children learn that the sooner they can grow into successful and appreciative adults!
Never underestimate the power of "thank you." This goes for both you and your child! Actively saying thank you for things your child does for you makes them feel good about their own good deed.  It will also remind them to be grateful for things done for them.  However, simply saying "thank you" because it's expected can become a mundane habit.  Take little moments to collectively think and talk about the things you're most thankful for.
Showing and having a greater sense of appreciation has a number of benefits for your growing child. First, they have more joy for the little things that grows into overall happiness. It makes them more inclined to help others in their personal life and community.  Being grateful improves their relationships with others as well.  Expressing appreciation for others develops positive feelings and connections.  Being appreciative will help your child grow into the happy, healthy adult we know they can be!