Never overlook calling home. Most parents or guardians are supportive. In most cases, I let the student know I plan to call home. If you suspect the child's parent or guardian may be uncooperative, or abusive, check with the counselor or with an administrator who may know the family. Never assume that because the parents don't attend school functions or don't call you they don't care about their child.
Many parents work long hours.
When you talk to the child's parent or guardian, mention the positive as well as the negative. Call home sometimes just for good reasons, too. Never make promises or threats you won't or can't follow. It will only make everything worse in the classroom if you lose the respect of your students. You can raise your voice but never engage in shouting matches with your students.