As I've alluded to previously, in addition to livestreaming, we do Hangouts On-Air... hundreds since late 2011. Currently 3-5 a week. We have a staff of over 20 people that just manage Hangout production and a freelance network of 100s around the world that we keep pretty busy.
We are often asked for tips. Here are the key tips, in my opinion... for Hangouts On-Air.
1) Hangouts On-Air are EVENTS. When we hang out with our friends, we don't care if they are dressed well, lit well, speak loudly, or show up on time. When we prepare an event for possibly hundreds of people these things become, well, useful. If you want to build a business or marketing plan around hangouts on-air, you need to treat them like an event for 1000 people, not a backyard BBQ.
2) The most important element is the host. Many hangouts suffer from poor hosting. It doesn't mean that the person isn't very knowledgeable, very famous, or very nice. Hosting is an entirely different animal. It requires both a structured mind and a little bit of attention deficit disorder. The key is that the host needs to become bored BEFORE the viewer. They need to push the participants to elaborate when they're not clear, and stop when they have said enough. The host should rarely be the content expert. Watch others to learn the process. In my opinion, (who I have the luxury of working in the same building with) is the most engaging and conversational host in the world. He is, in my opinion, the gold standard for how to move a conversation from subject to subject and person to person. It's easy to watch him... he's on all the time at TWiT.tv
3) Prepare your participants. Many times people will invite participants that have never used a Hangout into their first Hangout On-Air. The result is often confusion, and poor audio or video quality. One weak connection affects the entire event. We have an entire team focused only on the participant prep for Hangouts. It's that important. Look for fast connections and make sure they are all wearing headphones of some sort. We painstakingly prepare nearly every participant in every hangout, send kits for some and even teams for others. Beyond "surviving" the event... low stress setups lead to more fluid hangouts. Participants are the flowers in your hangout bouquet... drag them along the asphalt right before the event it's not going be nearly as pretty as it could have been.
4) Bookends - Know how you're going to get into the Hangout and then out of it. One of the weakest parts of many hangouts is the open and close. I can't say that we always get it right, but we are always working a plan. For many clients, we only administer the hangout itself to make sure these are as clean as possible.
5) Community is the Content - While the vast majority of Hangouts are singular events, often the most successful Hangouts are campaigns. Hangouts are an important part of a well rounded social diet. When the Hangout is out there by itself, it does OK. When it's part of a larger conversation with the community, it is much more powerful. Look at how to create an ongoing conversation in G+ Communities, Pages, Twitter and even Facebook... where the hangout is highlighting and processing the conversation that's happening across the socialsphere.
6) Why Live? In our opinion, there are only three reasons to do a live event; sports, news, social interaction with the viewers. Find ways to engage your viewers past just the participants in the hangout. This can be through twitter, Facebook, or G+ comments. Creating repeated events and constantly including the general viewing public continually creates a feedback loop that is very beneficial to your brand and your Hangout.
7) Hangouts are about Conversation - While it's important to plan, Hangouts are about conversation. The more freely this happens, the more engaging the event will be. We often see incredible conversations before broadcast that quickly dissolve into a "format" that someone thought would be more powerful. Authentic conversations among passionate people make the event.
8) Just Do it - Hangouts+YouTube is an extremely powerful platform for causes, businesses, educators and even just folks with an idea. There's nothing else like it and it's constantly improving. Get in when it's growing. If you wait until it's "done", the best real estate will be gone.
Anyway, I hope that helps... at least a little.