When presenting online, the main goal is to keep your audience’s attention. What usually works during in-person presentations does not always translate well with a virtual audience. Engagment is the key.

Lighting: The best flattering lighting comes from a soft and diffuse natural source, so always face a window (avoid direct sunlight) or a large light source , the larger the better.   You can also use a table lamp with a white shade positioned behind your computer. You can also use lamp without a shade that will bounce against a white wall or a large white board such a tri-fold corrugate display board.

Here are some possible setups with a basic table lamp:

Never have your back towards a bright light or a window, as your face will end showing up darker on the screen.
The best way to identify the ideal source of light in your home or office, is to use your phone camera in selfie mode and move around while looking at the effect of the light on your face.

Camera angles: Avoid having the camera too low or too high. A bit above  eye level is the best. Use books to raise the level of you computer.
Do not sit too close or too far from the camera. A good rule of thumb is to leave a space of three fingers between the top of your head and the top of the screen.
Remember to stand upright and not slouch, hunch or shrug. 

Sound: Good sound quality is essential. The computer internal microphones work but are usually not ideal. Apple earpods are better but make sure that the microphone (located where the volume controller is) does not rub against you clothes. Airpods are even better. A dedicated microphone like the USB Blue Yeti is among the best options.

Clothing: Do not wear plain white or black, best are neutral colors.
Avoid wearing noisy clothing or jewelry that will make noise when you move your body or hands.

Background: Pay attention to the background. Do not have it too crowded with objects that will distract the viewer’s attention. When facing the camera, pay attention to what is just behind you as you do not want a plant or a trophy sticking out of the top of your head.
If you plan to use a virtual background and do not have a green screen, have a plain light color wall or use a white bed sheet as the background. In this case, do not wear anything that has a color close to the background to avoid confusing the software. Test before going live

Bandwith: Internet bandwidth is crucial to a flawless presentation, If you are streaming from home, make sure that nobody is gaming or watching videos online as this will slow your connection and affect the flow of your presentation. Same for TV if your internet connection is through a cable company.