Speak with Conviction
So often when people are called to speak up in front of others, they become overly cautious in their fear of offending anyone. In so doing they may use phrases such as, "I think it might...." or "It's kinda like this..." or "It could be..." These are indefinite and vague and it is one way to lose your authority and credibility as a speaker.
Make a decision, make a stand for what you believe in and commit. Own what you say and speak out with confidence and conviction. If you're not sure of your facts, don't use them. Speak only about what you know and be sure you can back up your claims. Your audience will feel when you're feeling uncertain. They will read it in your body language and if you are not emphatic, they will lose confidence in your words.
Stand up and Speak out!