I had a meeting booked at 10am today, by phone and just with one other person. I was delighted when he called me right on time. I made an immediate judgement about him that set the tone for the rest of the conversation.
In the virtually-real world the traditional non-verbal clues are mostly missing: we can't make judgements based on buildings, furniture, clothes and other factors. Yet we still have to form relationships and work effectively together, even if we never meet in person.
One of the best ways to establish rapport is to be clear and professional in setting up a meeting: What date and time? What time zone are you operating in? Who is expected, who is optional? What phone number(s) or other technology (like screen-sharing) will be needed?
Then, when it comes time for the meeting, make sure you're on time, even if others are not. And don't be early, by much, either: if I expect you at 10am then a call at five minutes before might be just as inconvenient as if I'm left wondering whether I got the details right if you're five minutes late!