BismIllah wa as salaamu alaikum wa Rahmat Allah.
This subject is extremely important. Raising children is not something that can be left to chance. It is our responsibility and they are an amanah (trust) from Allah to us. We cannot rely on others to instill Islamic values in our children. We cannot rely on videos and cartoons to teach them how to make wudhu, pray, etc. We cannot expect to bring Islam alive and make it vibrant and exciting in our children's lives if we do not invest our time. There is no replacement for our time, effort, and attention.
Shabaan is the time to tell your children that the good deeds are sent up to Allah in Shabaan and brainstorm some good deeds to do. This is the time to start getting your children prepared for fasting by doing some test runs. Mondays and Thursdays, the white days of the months, or even just a day or two just to get in the mood and send up some special good deeds, insha'Allah.
Ramadan is here. This is the time to read stories about Ramadan. This is the time to read them age-appropriate information on what the fast is about and how to do it correctly. This is the time to see how each child can be a part of the fasting experience. Tell them what the special Sunnahs are for fasting, such as breaking the fast with dates and water. If there are things that are against the Sunnah, such as overly extravagant iftars, explain to them about the simplicity of the Prophet's food and that it is preferred to keep things simple. Model it. Do not tell them to eat in moderation and yourself eat until you cannot move. When Zakat Al-Fitr time rolls around, have them help choose what staple goods to donate. Have them help measure out the food, so they learn what a sa' is.
Children learn and develop avid interest through involvement and active participation. Keep your children in the picture, by which I mean tell them what's going on and why throughout the Islamic year. It requires discussions, ideas, and most of all, time - your time. It is invaluable and irreplaceable...and it makes all the difference.
If it benefits, then al hamdu l'Illah.