Eye contact - Look into the camera when you are recording. It will appear like you are making eye contact with the audiences when they view your video. This will result in a more engaging video.
Pace yourself - Avoid speaking too quickly/slow and pause when needed.
Practice, practice, practice! - Remember to practice your speech before the actual session so that you can speak clearly and with confidence.
Time yourself - Keep track and record the duration of each portion of your speech.
Familiarise yourself with the technology used.
Lastly, try a few takes when recording to test lighting, sound, focus, etc.
Before you begin preparing your slide, here are some recommendations on how to prepare your 3MT slides: