1. Predict the future. You can anticipate 90% of the interview questions you're going to get. Three of them are listed above, but it's an easy list to generate. "Why do you want this job?" "What's a tough problem you've solved?" If you can't think of any, Google "most common interview questions." Write down the top 20 questions you think you'll get.
   
   
2. Plan your attack. For EVERY question, write down your answer. Yes, it's a pain to actually write something. But it makes your answer MUCH easier to remember. That's important. You want your answers to be automatic. Having to think about your answers during an interview can cause stress, stumbling over words, and overall make you look unprepared. 
   
   
3. Have a backup plan. Actually, for every question, write down THREE answers. Why three? You need to have a different, equally good answer for every question because the first interviewer might not like your story. You want the next interviewer to hear a different story. That way they can become your advocate.
   
   
4. Prove yourself. Every question should be answered with a story that proves you can do what you're being asked about. "How do you lead?" should be answered with "I'm a collaborative/decisive/whatever leader. Let me tell you about the time I …." Always tell a story or have facts to prove you are what you say you are. 
   
   
5. Read the room. All that brainpower you're not using to desperately come up with answers to questions? Look around. Focus on the interviewer. In the first 10 seconds, is there anything in their office, or about them, you can notice and use to forge a connection? A book on a shelf? A family photo? A painting? Read the interviewer: is their body language open or closed? Are they tired and should you try to pep them up? Do they like your answer or should you veer in another direction? Reading the room and making a connection can be the difference between average and fantastic when it comes to interviewing.
   
   
6. Make it to Carnegie Hall. How do you get to Carnegie Hall? Practice. Same goes for getting a job. When I was in my second year of business school, I practiced my interview answers -- out loud -- until I could tell each story smoothly, without thinking about it (but not so smoothly that I was bored with the re-telling). My roommate walked in one day to find me sitting on the futon reciting why I thought I was a great leader again and again. He figured I was stuck in some kind of Stuart Smalley-like self-help loop. But I got 7 job offers from 5 companies (that's another story) and was on track to get another 6 before I stopped interviewing. How is that possible? Practice.

Dress to Impress (Not Distract)

While you want to dress professionally (again, from head to toe, not head to waist), don't just pull out any old interview outfit—take care to make sure what you're wearing works for video. "Certain colors, like many shades of blue—royal, navy, sky blue—look great on video, while others like reds and hot colors like magenta can be too bright," says job search expert Alison Doyle.

For the ladies: Pay particular attention to anything that might be a distraction, like jewelry (anything too bright will come off "sparkly like a disco ball" on screen, says Paul Bailo, a digital marketing technology executive and author of The Essential Digital Interview Handbook). Same with showing too much skin—a lower-cut top may look fine in person, but when you're only visible from the chest up, it can seem like way too much.

Also, as any makeup artist will tell you, what looks great in person can be quite different than what looks great on screen. "It's OK to use a little more than usual, as makeup tends to not show up as well on camera," says Hasti Kashfia of DotComplicated. "For those with oily skin, go for a matte primer—for dry skin, try a radiant primer or tinted moisturizer," recommends celebrity makeup artist Pati Dubroff. Then, "brighten under the eyes and spot conceal where needed." She also recommends a good dose of (professional) eye makeup: "Use a deep colored eye pencil [black or brown] and smudge at lashline, then curl lashes and apply multiple coats of mascara."

Master the Digital Handshake

Just like your in-person interviews, first impressions really matter. "The first five seconds will make or break your digital interview," says Bailo. "It is those few seconds, when the hiring manager sees you and you see the hiring manager that the digital chemistry is created. That is when this person hopefully thinks, ‘I like what I see, I want to engage in this digital conversation.'"

The first step to creating that digital chemistry? What Bailo calls a "digital handshake." Think a "slow, confident, professional, firm nod" with "a slight shoulder bend and eyes forward—the other person should not see the top of your head." When you can't physically greet the hiring manager, this simple gesture shows that you're excited to be there and ready to get down to business.

From then on, focus on keeping your eyes on the camera—not on the view from your screen. "Your eyes need to look straight into the camera, so it appears on the other end you are looking right at the other person," says Bailo. His tip? "Try downloading a photo of the hiring manager, printing it, and making a hole in the photo to allow the camera lens to see through. Now you can look at the photo, which makes it more human to conduct your digital interviews." (Just keep it small—you still want to be able to see your screen!)

Don't Forget Body Language

"Someone I was Skype-interviewing with was so motionless, I thought for a while the screen was frozen," a colleague recently shared with me. Lesson learned: Make sure your body language expresses that you're engaged and, well, alive. "As you're communicating, lean forward," suggests Bailo. "This will show interest and concern and will engage your audience. It will also convey eagerness and willingness to listen."

Just be careful not to overdo it. "Even more so than in an in-person interview, avoid excessive physical movements," says Dubroff (think making large hand gestures and wildly nodding or shaking your head). "You'll appear blurry to your interviewer, and none of your facial expressions will be visible."

Create a "Skype Studio"

If you're going to be doing a lot of interviewing—or really want to make an impression at a high-stakes meeting—consider creating a mini-studio at your place. Find a quiet corner, buy a roll of seamless paper (Bailo suggests "professional background paper in a nice neutral color that does not compete with your wardrobe"), and hang it from the ceiling. Having a clean, simple backdrop not only looks professional, it makes sure that the interviewer focuses on you and only you.

To perfect the look, add lighting. "Soft, natural lighting is the way to go," says Bailo. Try having "three lights, one to your right, one to your left… and the third shining up at your background. This creates a wonderful, inviting, caring environment."

Finally, consider investing in high-quality sound equipment. "The essential part of the digital job interview is the camera—get a name brand HD web camera," says Bailo. He also recommends upgrading your mic, which will make sure that every word you say is heard loud and clear. "Blue makes an outstanding product specifically for interviewing called the Snowball—you are going to love it and sound fantastic!"

A good Youtube video covering how to look good on Skype is: http://youtu.be/rQwanxQmFnc