Just know that even if you preview the space before your presentation, there are still some things that are beyond your control. Don't sweat it. Just apologize to your audience for the inconvenience and continue sharing the powerful information that they expect from you.
Once you have a clear understanding of your audience, the environment, and what information you can present that will best serve them, it's time to finalize the information that will be in your presentation. In other words, you need to come up with a speech that will knock 'em dead or at least make them feel that you actively tried to meet their expectations or fulfill their needs. As you sort through the information to determine what elements actually make your presentation, keep in mind that the focus should not be on what you need to say but what your audience needs to hear.
As long as you keep your focus on your audience, you'll never get off course.
Write down a specific statement of purpose for your presentation. This is an important first step because you can't develop a presentation until you can clearly and concisely express the specific goal of your talk. Clearly state the reason for your presentation and why you're the best person to deliver this message. Even if you don't initially think you're the best person to give this talk, convince yourself that you are for the purposes of the presentation. That will help build your confidence and get you in the right mindset to give a great speech.
Once you're clear on the purpose of your speech, you need to sort out the elements that you believe are absolutely necessary or just nice to include. Sometimes we get so excited about the topic we think we need to include everything but the kitchen sink. Although that might excite you, this approach will probably bore your audience to tears. A great speaker strikes a balance between what he wants to say and what the audience will be open to hearing.
Refer back to the K.I.S.S. (keep it short and sweet) principle. This mantra will help you design a message that's clear, convincing, and interesting while using as few points as possible. Start by listing all of your key ideas. Then think about the time that you have allotted for your presentation. Next, review the points to determine which ones you can realistically explain in the time frame you have available. More importantly, focus on the elements that will be most meaningful to your audience.
If you're clear on your purpose, your audience needs, the environment where the talk will take place, and the how you believe your audience will respond to you, it's time to complete your outline. This will help you express and expand your central idea, using key supporting elements. The process is similar to developing a preliminary table of contents for a written report.