bandwidth. If you do not have a strong and steady connection to the Internet your experience will be diminished. The picture will freeze, the audio will warble or drop out and you may even lose connection altogether. Dropping in and out of the same hangout is not cool. Be considerate of the others by stopping after one or two failed attempts if the problems are on your end.
Next you have to be prepared with the right sound equipment. A headset is preferred to avoid the sound feeding back into the microphone. A lower cost alternative is the use of ear buds like the ones that came with your iPod or smart phone. Ideal is a sound system with noise cancellation but this is a bit more sophisticated and unnecessary unless you plan to appear in live shows where headsets can detract from your otherwise cool appearance.
Last is the camera. Most people recommend the Logitech C910 for its superior value. A high definition camera with the proper lighting can make you a star. Keep as much white out of your background as possible and watch for bright spots or shadows on your face. Don't sit too close to the camera. Take advantage of the preview screen and position yourself so the picture contains the top of your head to the middle of you chest.
Obviously your hardware must also be up to the challenge. The bandwidth will be wasted if your computer does not have adequate processor speed or memory. A large monitor or dual monitor setup is preferred. The thumbnails in a hangout (the smaller windows showing all the participants) are high resolution so they truly benefit from more screen real estate.
Basic hangout etiquette has also been covered by many. Most suggestions are common courtesy such as no shouting, talking over others or generally being rude. Less obvious are tips like muting when you are not actively speaking, if you are typing or take a phone call. Remember a hangout is self directed so any noise you make is going to put you on the big screen. No one wants to watch you while you are on the phone or relaying a message to your colleagues at work.
There are many more tips and tricks on Google Plus but it might be more effective (and a lot more fun) for me to show you than continue writing. Drop me a line and if you have all of the prerequisites included above then let's go ahead and schedule a hangout together.