I'm going to make a concerted effort to focus more of my advice toward beginning photographers. As I read through all the photography forums, including the Photographers Cooperative, I see lots of advanced techniques, and that's awesome... but for beginners, it really isn't that useful. So here are three very specific things to try in order to get better portraits, today!
It's All About The Eyes!
When you take a portrait of someone, the thing that needs to be SUPER sharp in focus is the eyeball, closest to the camera. In the photo above, the element that really catches your attention is the baby's eyes. The very first place your eye goes when you look at the image is her eyes, and my guess is that your attention stayed there for a while. Your camera may have a lot of different focus modes. (It probably does, even if it's an entry level model.) It's worth finding out how to adjust the focus mode, and get it set to where you have just a very specific area in the viewfinder that is focusing. When I'm doing portraits, even though I have a gazillion focus points available, I set it to be just one single point. And that point gets lined up with the subject's eyeball. One of the first things that will really make your portraiture start to 'pop' is when you get some insanely well-focused eyes. The human brain connects to other humans through eyes, and that connection carries over to photos. TRY IT!
Chill Out, Yo!!!
Almost everyone is now comfortable in front of their own lens, taking a selfie. People are photographed more in a week in the 21st century than they used to be photographed in a lifetime. But still, when it's a 'real' camera, and the photo is being taken by someone else, the subject can feel very uncomfortable in that situation. Here are some thoughts:
Be relaxed and easy going with your subject.
When you have captured something that looks great, get excited and show them! It will give them confidence.
Don't rush your settings - slow down, take the time you need to set up your camera correctly.
If something works really well, do plenty of that - but don't forget to keep trying new things, too.
If something doesn't work, try to figure out why.
If your subject is of legal drinking age, and isn't driving, consider offering them a glass of wine. Not too much, because it will start to show in their complexion, but just a bit can really settle the nerves, and relax them for the shoot.
Experiment with Low Aperture Settings
Everyone loves those photos where the model's eyes are super sharp in focus, but the background is just buttery smooth and blurry. The image above was taken for an ad campaign for the piano manufacturer. The focus is on the little boy, and we just wanted the "mood" of the parents looking on in the background, but attention needed to be on the boy, and the piano. Even though I was shooting with off-camera lighting, and could have used any aperture I wanted, I used f/2.8, so that everything behind the boy (and in front of him) was blurred out. There are a number of things that go into creating that "look." The number one thing is your aperture setting.
We have a couple of more detailed posts on aperture by Aaron Taylor, I have linked them below. For just starting out, the simple rule to create that blurry effect in the background is that you want plenty of distance between your model and whatever is going to be behind them. (Don't stand them right next to a wall, stand them 15-20 feet in FRONT of the wall.) Next, you want to set your aperture to one of the lowest possible number settings. It may be 3.5, or 2.8, or if you are really lucky, even lower. Whatever that lowest number is, that's the aperture that will smooth out the background the most. If you want to see the difference, bump it up to 11, or 16, and see how much more in-focus your background will become. That's a SUPER important photography skill to get good at manipulating. (Secondary tip on this one... if you aren't really good at manual mode, don't waste time trying to figure it out while working with a model. Just set your camera in Aperture Priority mode. That will have the camera's computer auto-select your shutter speed and ISO settings, and YOU control your aperture. A great way to learn what the different apertures are going to look like!)
Depth-Of-Field - It's More Than Just Aperture