The next time your child makes a request that you'd normally say YES to, intentionally answer YES with heightened enthusiasm and joy. As you do this, feel the extreme "yesness" of your response...
YES-energy can also be expressed as optimism, clarity, certainty, peace, alignment, flow, presence, etc. — with or without a literal YES. It'll soothe (and often satisfy) your child when a literal YES isn't practical.
You can't "spoil" a child with too much YES-energy. The way to spoil children is to give them too many literal YES's that are devoid of YES-energy, such as when parents are self-sacrificing or afraid of how their children will react to a NO.
Today, set the intention to amplify your YES-energy every time you respond to your child — regardless of whether your literal answer is YES or NO. This is one of the best ways for you and your child to establish a pleasurable, cooperative "groove."