Use a rubric that considers three elements of the speech-giving process: nonverbal skills, verbal skills and the content of the speech. For nonverbal skills, evaluate eye contact, body language and poise. Give a grade for enthusiasm and elocution in verbal skills and scores for subject knowledge, organization and mechanics in the content area. Assign a grade of one through four, with four being the highest possible score in any category.
Instead of assigning students a numeric score for their speeches, evaluate them with a label of "distinguished," "proficient," "apprentice" or "novice." The categories for the rubric should include sections on awareness of audience; strength of material, organization; and delivery. You can develop your own points for comparison. However, an example is "Clear purpose and subject" and "Pertinent examples, facts, and/or statistics" for a distinguished rating in the strength of material and organization category.
You may want to assign an accurate distinction to the students without using numbers. Have categories labeled content, delivery, organization, creativity and length of presentation and assign levels of superior, adequate, minimal and inadequate for each category. For example, a score of inadequate in content would consist of the student "[focusing] primarily on irrelevant content" and "[appearing] to ignore the listener and the situation." On the other hand, a score of superior in length would consist of the speaker being within two minutes of the appropriate time.
Sometimes students conduct presentations in which they present pictures, videos, charts and so forth to accompanying their speeches. You can use a numerical system, with values from one through four, and include categories of organization, subject knowledge, graphics, mechanics, eye contact and elocution. A speech with a score of one in the graphics category would include no graphics or irrelevant ones, while a speech that scores four in the same category would include graphics that support and enhance the subject matter.