We introduce ourselves to make ourselves known. We introduce others for the same reason and whether it is one-on-one or presenting someone to a group, the protocol is much the same.

• Use both the first and last names in your introduction. Just as I know four men named Mark, help everyone to differentiate who you are talking about. You are introducing the whole person.
  

• Know something about the person. When introducing two people, sharing information about common interests will help them start a conversation. When presenting a speaker, you appear professional and prepared. 

• If you find yourself caught by surprise or unprepared, the less said the better. Rambling on provides you with opportunities to make erroneous statements and show your ignorance.
  

• If necessary, it is perfectly acceptable to ask the person you are presenting to help you out. After introducing him by name, follow up with  "Mark, would you please share something about yourself ... what you do ... your interests ..." etc. 

• When introducing a presenter or speaker, ask for an intro in advance and then follow it, or a close version of it. Mention the purpose of the talk but avoid going into detail as you may be intruding into the presentation itself. Following up with "Please welcome ... " is always a good transition.

The purpose of an introduction is for other people to become acquainted, to learn from each other, to form some sort of bond. Not to listen to you.