With the research process.
With writing the speech body.
With the selection of visual aids.
With topic selection.
The obstacles that may affect the speech.
How much information the audience will need.
The general purpose of the speech.
The expectations and reactions of the audience.
Use more open-ended questions than closed-ended question
Make no assumptions about your respondents
Avoid biased or leading questions
Use a clean, consistent structure for the overall questionnaire
Here's an interesting quiz for you.