The main thing to consider when choosing an economic system is what sort of society you want to have. You will want to choose a different system depending on what your vision of an ideal society is.
If you want the maximum possible amount of freedom and economic growth, you will want to choose a market economy. Market economies are based on people making their own economic choices. Because market systems rely on the profit motive, they tend to be the best at creating a wealthy society. Thus, they provide economic growth and the chance to make your own decisions.
If you want the potential for greater equality, a command system would be the way to go. In a command system, the government decides how the economy will run. If the government does not want a lot of inequality (a common problem in market systems) it can create a system in which there is not much of a gap between the richest and the poorest people.
Finally, if you want stability and predictability, a traditional system is best. In such a system, things are done as they always have been done. This eliminates doubts about how things will happen. For example, you will make your living the same way your mother or father did and so you do not have to worry about choosing the right career.
An economic system should be chosen based on which of these outcomes seems most desirable.