There are three basic methods in which to hold ownership of property. First, you can own property in your sole name. Second, you can own property in your sole name with a beneficiary designation, such as an IRA or life insurance policy. Third, you can own property jointly with another individual.
Ownership of property is very important in determining what assets must go through the probate process. Upon your death, the property you have in your sole name with a beneficiary designation would pass to that beneficiary without the need for probate.
If you own property jointly with someone in the format of a joint tenancy or tenants by the entireties, that property as well would not be probatable. Generally, the only property that is probatable is property in your sole name with no beneficiary designation.
Using this information, one can completely avoid probate by making sure you have the beneficiary designation on all of your assets or that you jointly own property with someone else in a joint tenancy or tenants by the entireties situation. I can discuss various techniques with you that can allow you to avoid probate.