I am an amateur, as in "lover of", photography. I love cameras as tactile devices, I love how photography makes me consider the world as art, how that little viewfinder can reveal unknown beauty in well-known places or people. And I love looking at my photos, and remembering vacations and meaningful moments. For me, photography is about finding beauty, and capturing memories.
However, most of the writing on photography seems to be focused not on my needs, but the needs of professional photographers: A super competitive field of visual artists who compete on image quality and novelty, and use crazy and expensive gear. I have found many of their lessons not applicable to my amateur needs, or even actively detrimental:
Embrace the noise
Many pros limit their ISO numbers, because high-ISO noise is ugly. Which it is. But you know what is even worse for an amateur? Not having that picture of my baby, because it was too dark.
So I set my ISO to unlimited, reduce my shutter speed and aperture so I actually have a chance of capturing my fast-moving toddler. And embrace the ensuing noise. Some of my favorite pictures look unbearably noisy on my 4k screen, but look just fine when printed, or on a smartphone (the two most important mediums in the world). Because of this, I find noise reduction rarely worth the effort. Color heavy noise reduction works ok, but anything else looks worse than the problem. I vastly prefer a sharp, noisy shot to a mushy denoised shot with no detail.
Step it down
Another common Pro argument: Wider apertures are better. Which they are, at capturing light, and blurring the background. But as an amateur, a wide-aperture super-shallow depth of field just makes me miss shots. At f1.8, the area in focus is barely a few centimetres deep. I missed too many shots because I accidentally focused on the nose instead of the eye. So, in the absence of studio lighting, and arbitrarily many retries, I prefer to step it down and live with the noise, if need be.
As a fun corollary, all those fancy prime lenses with crazy-wide apertures, they are simply wasted on me. Anything beyond, say, f2.8, is not something I need to spend money on. Also, lenses are noticeably sharper when stepped down! I have been disappointed with the sharpness of a number of shots because I forgot to step it down. Nowadays, I typically shoot at f5.6 or f8, and only go wider if I actually need to, because of lack of light, or if I specifically want a blurry background.
Wide-ish lenses are easier
I wondered, for a long time, why pros seem to like long-ish lenses for portraits: The answer is, because longer lenses have a shallower the depth of field (for the same f-number), and pro photographers love their blurry backgrounds. But as I said before, that is not for me.
Instead, I prefer wide-ish lenses. If something is too small on a wide-ish lens, it is usually no problem to get a bit closer or to crop afterwards. If something is too big on a long lens though, backing off is often not possible, and you miss your shot1. Plus, wide-ish angles don't blur as much from shaky hands, and are more compact. They often focus more closely, too, which is a huge bonus if you want to take pictures of a toddler.
I have tried, unsuccessfully, a 50mm and 35mm prime (APS-C). Now I own a 27mm pancake prime, which I find perfect: long enough to get nice portraits, but still wide enough to capture a landscape.
Be careful with super-wide angle lenses, though. Even though they are a ton of fun, I have found anything below 16mm to be very difficult to use effectively. It's just too easy to get that fisheye-distorted look, especially near the sides. That distorted look, by the way, is caused by being too close, not by lens distortion. The same thing happens if you take a longer lens or a cell phone and get too close. Just don't do that.
Pros use the biggest sensor they can get, to get the best image quality possible. But that also makes everything else much more cumbersome: Bigger sensors mean bigger and heavier bodies. And bigger and heavier lenses. And shallower depth of field (see above). And smaller focal ranges, hence more lens changing. And, not least of all, much, much, much higher prices. It is not for me.
To some extent, the same goes for different quality levels: Personally, I have found entry-level APS-C mirrorless interchangeable lens cameras a good compromise. These entry-level plastic lenses and cameras are usually smaller, lighter, and cheaper than their higher-end brethren, but compromise on robustness and aperture sizes (e.g. Fuji X-E2 375g/€250 + Fuji XC 16-50mm, 195g/€150 vs. Fuji X-T1 450g/€250 + Fuji XF 18-55mm, 300g/€250 vs. my old Nikon gear). And for my everyday camera, I' take a smaller, pocketable camera over a "better", bigger one any day.
Haptics are important, too. I have seen great cameras and lenses that just didn't feel good in my hand. Which meant I wouldn't ever take them with me, and wouldn't take any pictures with them. I now go try stuff in the store before I buy anything. This has talked me out of a number of unnecessary purchases, internet consensus notwithstanding.
And finally, I buy used gear. Cameras and lenses depreciate about 70% within the first two years, without losing any quality. A great camera from two years ago is still a great camera, but costs a third of the original price, and can be resold without loss. And is better for the environment. Win-win-win.
I have found many "common" rules about photography useless for my amateur needs. I have found cheap, plastic, used gear more useful than pro gear. I have found noisy, small-aperture pictures to be better at capturing important memories than clean, "professional" ones. I have found haptics, size and weight to be much more important than ultimate image quality (within reason).
The funny thing is, you don't find this kind of information on the internet, since most review websites seem to focus on the professional viewpoint, even for gear that is clearly meant for amateurs like me.
You need to back off much farther on a long lens than you have to move closer on a wide lens.