Shooting manual
Shooting with the camera in manual mode is probably the most intimidating skill to new photographers. It’s not that it’s particularly hard, and there are definitely more complicated skills to grasp, but it’s one of the most visible challenges when you first pick up a camera: how do I use the M on the dial? It’s a sign of status, separating the real photogs from the snapshotters.
Which is crap, because placing technical skills on that kind of pedestal is losing sight of that fact that only the final image counts. Your audience won’t give you bonus points for shooting in one mode or another, and knowing how to shoot manual does not automatically give you the vision to use it. If you’re taking boring pictures in automatic, you’ll be taking boring pictures in manual. Composition is entirely in your eyes and your brain, and all manual mode, or any other feature of your camera, will do is help you translate your vision into a photograph.
That said, learning how to use full manual or one of the priority modes gives you control over the image. The camera cannot read your mind, and unless you understand how aperture, shutter speed, and ISO interact to control the exposure and depth of field, you’re going to up missing shots. Guaranteed. Technical skills are vitally important, and you can’t ignore them without sacrificing your potential as a photographer — not to mention if you spent a lot of money on a camera that can give you this control but refuse to learn it, you’d have saved a lot of money by getting a cheap compact.
But full-manual mode is probably less important than understanding metering modes, white balance, or shooting in RAW and post-processing, for example. It’s easy to do, by the way, once you’ve learned to read the camera’s light meter in the viewfinder — you’re not expected to just know what shutter speed you need to get a proper exposure with a given aperture.
But bear in mind that setting aperture and adjusting the shutter until the meter looks good is no different than shooting in aperture mode and setting exposure compensation, unless you need more exposure compensation than your camera can do — which isn’t likely, except in specific circumstances. If you trust the camera meter to tell you when you’ve turned the dial far enough in manual, you can trust it to turn the dial for you. Just remember you can’t trust it to turn all the dials for you.
(Exposure compensation, in case you haven’t used it before, is easy and useful. Most of the time your camera is metering with the assumption that you want the scene to be, on average, an even, neutral gray — in terms of brightness, not color. Setting the EC will adjust the target exposure, in case you want it brighter or darker than that, or if you’re shooting something that will fool the meter. For example, it’s hard for the camera to know that snow is really supposed to be white in color, and it usually needs about +2/3 EC to get it right. Or if you don’t mind underexposing just a touch to get a slightly faster shutter speed, you can use -1/3 EC.)
Anyway, if you’re intimidated by the big M, try using shutter or aperture priority. Experiment with those modes until you have a good sense of what you’re doing when you’re changing the aperture or shutter, and I promise you your ability to create images you’re proud of will increase 10000%. And don’t listen to anybody saying ‘real’ photographers do this or that. There’s nothing wrong with mastering one new thing at a time, at your own pace, and shooting manual does not have to be at the top of your list.