When starting to think about a speech topic you can help yourself along by asking five simple questions:
Regardless of whether you are conducting an interview, preparing a persuasive argument or preparing to inform your audience you will go farther by first answering these.
Who? This could be, "who are you?" or "who will be affected?" or "who favors this?".
What? Could take the form of "what did you do this summer?" or "what will be the cost?" or even "what will have to change?".
When? You can ask yourself "when will it take effect?" or "when will people learn?" or "when did you decide to run for office?".
Where? Sample questions might be taken from "where will we find the money?" or "where did you go on vacation this summer?" or "where is the advantage in change?".
Why? These questions might be taken from "why did you choose a faith-based school?" or "why should we support this?" or finally "why did they make this law?".
This isn't meant to be an all inclusive list, just sample questions. As you approach each topic you can look as these questions and get a feel for how easy or hard it will be to develop a speech by the ease with which you answer them. Advance preparation is often the key to success!