Decision making usually involves various different levels and the sooner the child is made to understand all the connecting levels, the better able to cope with the decision and its outcome will be. Understanding that decision making is not to be taken lightly is a very important lesson to impart to the child.
Choices

One of the first things the parent should try to instill in the child is the fact that decision making is not about simply wanting something and going with the first choice or thought to acquire it.

Teaching the child that there is a need to consider a lot of elements before the final decision is made, will help the child make better and well rounded decisions that are more likely to be accepted and followed willingly.

Perhaps conducting a simple exercise where everything is noted down on paper would be a good start to help the child be more aware of the various aspects involved in good decision making.

By putting things down on paper, the child will be able to see clearly all the options and intended desired outcome and thus have a more informed picture of what may be required as part of the decision making process.

This will also help to encourage the child to note down as many possibilities that can contribute to a more effective decision making process.

Insisting that the child learn to approach each decision tack with a few possible options will be one way of encouraging the child to think and explore in depth the elements that would be main contributing factors to the eventual decision making. There is also the added advantage of the child learning to look out for as many different solutions as possible.