Choose your words carefully. It is easy to speak from emotional anger that you have towards something that needs to be reprimanded. But in order to really get your point across your words, and how you say your words will be the ultimate deciding factor of your effectiveness. Say what you mean and mean what you say. Be consious of the consequences of the words you speak when reprimanding.
Sandwich technique. Start with a compliment, tell them what needs improvement and end with a compliment again. You want the reprimand to come in the middle of the compliments. This is the secret to effective reprimanding. Your words will be more effective when you use this approach.
Think bigger picture. Always look at the bigger picture. When your angry with a certain individual for an action they did that was way out of line, you must approach the situation with the bigger picture in mind. Always be in a calm and relaxed state of mind, before you think of attacking back. The person that looses their cool first is generally the person that doesn't get their message through clearly.