I think it is always a nice idea to have a little back story as to why a new VA has opened. Perhaps you and your team have "virtually" purchased a failing airline with a view to turning its fortunes. This organic growth of a VA can be lots of fun to manage and from a pilots perspective they can become involved in the process by captaining new routes or aircraft as they are rolled out.
Operationally choose your hubs/bases, routes and aircraft carefully.
It is always nice to start with multiple bases but in reality does that happen with real world airlines, rarely I suspect. Choose bases that have good scenery available in FS and perhaps offer a unique location rather than your typical major international airports.
Likewise with your fleet selection aircraft that are well represented with a choice of panels and sound packages are a must have. Ideally if they have payware models available you will increase your appeal. A mix of props and jets is nice as some pilots may have a preference for one or the other.
Schedules should offer a realistic blend of destinations and duration. How much time we all have available for FS varies hugely so having a mix of flights from under one hour to those that cover intercontinental distances is key. Then again would you want to offer international flight immediately? Perhaps this is something that could be launched (with a little pomp and ceremony) after you have found your feet and attracted a few pilots. Interesting airports and perhaps those rarely visited by "every other VA" can be fun. Mixed in with more common destinations your schedules can look fresh and help to attract pilots.
Keeping the website interesting and updated is important. Nothing worse than a website that appears to have no life in it!
Don't just focus on the opening of the VA. Have a rolling six month plan and keep revisiting it, tweaking and developing it.
Running a VA can quickly become a time consuming task. Be prepared to work hard and perhaps see minimal results initially. Pilots will come and go but don't be too concerned. Do you best to maintain the profile of the VA across the web with regular file uploads, press releases etc. Pilot numbers will stabilise after a year or so and with that base in place you can look to really establish and differentiate yourselves in a crowded arena!
Let me know if you want any more input and I look forward to your opening.
May your number of landings equal your number of takeoffs.....