It can distract the audience if you use wild hand gestures, bobbing and weaving back and forth, or have your back to the audience.
Give yourself plenty of time to rehearse to avoid word hooks like "hem", "uh", "like", etc. With practice, you’ll smooth-out rough edges and improve cadence.
Wear clothing that is comfortable and that does not clash with the backdrop
of the presentation/stage. This helps ensure you show up well for the audience and the camera. Avoid clothing with small patterns (checkers, herringbone, etc.) as this tends to create the effect of moving patterns on camera.
Avoid wearing lots of gaudy jewelry.
The lights and mics also pick this up and it can be distracting.
Speak clearly and speak just a little slower than you usually do.
Watch as many online Ignite videos as possible
This helps you become familiar with the format being done in different ways, and can give you great ideas for how to present your content succinctly, but completely. There tends to be a rhythm to Ignite talks and if you haven't seen an Ignite session before, this will help you understand better how they work.
Design slides that are visually interesting and tell a story
Avoid bullet points, lots of text, animations, and distracting backgrounds. Use visuals to make an impact and use your spoken words to tell the story.
5 helpful pages for speakers: