Have a conversation with the patient. When you see an elderly patient who looks down in the dumps, go and just talk with that patient. Many patients just want to have a conversation with someone who will converse back with them. I have found that just having a conversation with the patient, can have great results with their whole attitude.
Listen to the patient. Sometimes the patient just wants to be heard. Just sitting down, and lending your ear, can go a long way toward a better day. If the patient is angry, listening can have great results. Just tell the patient you will do your best to help them resolve the problem at hand, and then follow through and do all you can do. This also builds trust.
Show you care. Just a caring attitude is the best thing you can show a patient. Don't try and fake a caring attitude, a patient will see right through it. Don't go into a medical career if your not a caring person.