1) Never underestimate the amount of pre-event planning time required for a virtual event. Build it into your schedule. You'll always wish you had more!
2) If your event is for an internal audience, engage your IT department early to ensure attendees have sufficient bandwidth and any challenges with access are resolved beforehand.
3) Like a physical event, keep the content and delivery engaging. Vary your presentation formats to keep attendees interested.
4) Consider using the virtual event platform for pre-event communication. This will test out its usability with your audience, help attendees get familiar and comfortable with its use, and get the word out!
5) If live interaction is a part of your event, don't forget to build sufficient rehearsal time into the schedule.