If you try to trade with anything less, what happens to you will be luck. You won't have the capital necessary to apply proper risk management principles. Risk capital is defined as money you can afford to lose without affecting your standard of living. It should also be money that you feel comfortable risking. Think of your commodity account as an investment in a business.
Many businesses fail.
Make sure you won't be so afraid of losing money that it will affect your ability to make correct trading decisions. The next part of your trading plan involves how you will make your actual buying and selling decisions. There are four cardinal principles which should be part of every trading strategy. These building blocks are so basic and important that I have written a whole book about them. You should make sure your strategy includes each of these requirements for success.