Explain the principles of effective communication in the workplace

I am working in careers advice for IT personnel. I have been asked to produce a small booklet on valued employee attributes and communication barriers. I will write a report explaining the principles of effective communication.
Skills for General Communication
Question and answer

People at the workplace will always want to ask questions about what you have said. To avoid awkward questions do not talk about something which you do not know how to explain, and if you are going to include something in your presentation make sure you know exactly what it is and know how to explain it. When answering questions even when not sure about the answer it’s important to speak confidently as if you know exactly what to say, if you do it will seem that you know extensive knowledge about the subject. During my internship I had to do presentations and after questions were asked. I made sure I was comfortable with the topic I chose so that when I was asked questions
Engaging the audience
It’s important to keep your audience interested throughout a presentation. This is because if you do not then the audience will lose track of what you are talking about. Therefore they won’t understand what you are talking about and will become confused; especially if you are rambling and not making a clear conclusion. They may not understand the point you were originally trying to make and then the presentation will not be useful.
Skills for Written Communication
Grammar and Spelling
When writing things such as an email or presentation it is extremely important that all of your grammar and spelling is correct, because if it is not than the employer will immediately look down upon you. If you have bad spelling and grammar it will look that you don’t care and are not checking back through your work which is unprofessional. It’s important to show professional level of English as it will show employers that you will be useful at any writing task.
Structure
As with grammar it is important to structure when writing a letter or an email, there are many ways you can structure such as using sub-headings to put a point across, using paragraphs and a conclusion show that your thought or point has come to a close and labelling a letter in a professional way
Interpersonal skills
Body Language
When speaking to somebody its important to stand straight with your hands either side of you, this is because firstly standing with a straight back will allow you to speak loudly and clearly and will make you look confident which shows you know what you are talking about. Secondly if you keep your hands either side of you it is more professional than keeping them in your pocket and fidgeting.
Active engagement
It’s important to be actively engage in the conversation by showing eye contact and nodding. This will show that you are interested as if you show you are bored it will impact the other person’s communication and they may not want to interact with you again.