Don't be afraid of repeating and reiterating. It is better to pause and go over a point several times than leave your audience in the dark. Always leave time for a question period at the end. It is better to leave out some material, and give the audience to responde. It is also helpful to plant some one to ask the first question, to warm up the audience.
People are often shy to ask the first question.
If you do not have the answer to a question, admit it. Don't try to fake it. If the students or audience realize this you lose their trust. It is also helpful to have an evaluation form the simpler the better, to hand out at the end of your session. You will be surprised how many helpful suggestions you may get from your audience for t he next workshop or lecture.