Structure is your friend, because it can significantly increase your overall clarity. Remember that brilliant material wrapped in a convoluted package is not a successful lecture. Consider issues of clarity from your perspective first. You must clearly organize your thoughts in your own mind. If the structure is not clear to you, then it certainly will not be clear to your students.
That said, there is no single structure that produces clarity in every situation. Based on your topic, you may find it most effective to present a simple list, a classification hierarchy (with points and sub-points), a chained structure (in which you lead students through an argument or proof step by step), or one of many other options. You may even use several of these different models within the same lecture.
Think also about clarity from the student’s perspective. It is strongly advisable to give the students a roadmap for your lecture. If they know where you are going, they are more likely to follow you. Then indicate obvious transitions between points. Use repetition to emphasize particularly important points, and explain any technical vocabulary.
As the lecturer, the onus is on you to lead people along the path you set for them; the onus is not on them to discern your direction.