One way you can stop your children from spending your money recklessly is to spend it yourself before you die. Another way is to put all or some of the property you plan to bequeath them into a trust. You will name a trustee (who does not have to be the same person named as the children’s guardian) who will manage the trust until the children reach a certain age or attain certain goals, such as a college degree. You can have the trust turned over at once or gradually, such as one-half at age 25 and one-half at age 35. You can also set up what is known as a spendthrift trust, in which you instruct the trustee to carefully control how much money is released from the trust.

For more, see http://estate.findlaw.com/estate-planning/trusts/trusts-need(1).html