You should decide whether you want to hold the property so that if one owner dies, the other takes that interest immediately (joint tenancy), or if you want the interest to flow through the estate (probate required) of that person (tenants in common). Usually for happy spouses, you would hold it as joint tenancy. In most other cases, such as brothers holding land, you want to be able to will the land to other people (such as children), so tenants in common should be used.