Check the age requirements to execute a will in your state. Most states require a testator to be 18 years or older. Underage people's property passes according to intestate distribution laws, usually to offspring and parents. Most states require that a testator also be of sound mind. This means that the testator must understand that she is making a will, know who she wishes to inherit and comprehend her devises in a general sense.
Read through the form will and fill in the blanks. Insert your full name and address, and name an executor -- the person who administers your estate after you die. The executor gathers your assets, pays any outstanding estate bills and distributes your property according to the terms of your will. You can name as executor someone who is also an heir under your will. Check with the person you select before inserting his name to be sure he accepts the appointment.
Consider your devises. If you have myriad heirs, work out on scratch paper which heir is to receive what property. Enter the information in the devise section of the form will. Identify each heir unambiguously by full name, address and date of birth. Describe each bequest specifically. Use a parcel number or street address for real property, identifying account numbers for bank or investment accounts, and license plate numbers for vehicles. Consider naming a residuary beneficiary to inherit whatever you did not specifically bequest.
Add any conditions to your bequests. For example, if you only want your cousin to inherit your house if he survives you, add the condition to the devise and specify an alternative beneficiary in case the condition is not met. Name any child you disinherit and leave him a nominal devise of $1. If you omit mention of a child in your will, the court may consider the child "forgotten" and entitled to an intestate share.
Sign your will in the manner required by your state statutes. All states require that at least two adults witness a prepared will. Select people who are not heirs under your will. In their presence, identify the document as your last will and testament, then sign in the space at the end. Each witness signs after your signature.