Your children will copy you. They see what you do. They will become what you demonstrate, they will take on your behaviours. Children are sponges.

Therefore you should be who you want your kids to become. You are their role model. Act virtuously at all times, Summum Bonum, lead your best possible life.

Define your principles, constantly reflect, and ensure you have a goal system.

It doesn't matter how virtuous your words are if you are disingenuous in your actions.

Be gritty in how you live your life.

Reading is the greatest shortcut to self-improvement. They should see you reading (and writing). Make books a central part of your house and life.

You may be able to deceive them sometimes, but not all the time. When they notice that you haven't told them the truth or have misled them, they won't know when to trust you. Therefore it's important to never deceive them.