I find I’m doing more and more in black and white. Agree that shooting with bw in mind is best and set your camera to show bw. Another thing to try is google pro bw photographers and study their photos. It will be a revelation and generate ideas when you are in the field. Bw photography is a different field, with different rules and can be quite liberating. It’s all about contrast. Want to make the sky black to make your subject pop? Go for it. You are no longer trying to represent what’s real (very little is really bw), you’re just creating an image.

The most ubiquitous reason for choosing B&W is to remove colour as a distraction. Typical reasons for doing that are when you want to emphasise shape or structure or pattern or texture. Other possible reasons are that you may want to emphasise a story that the photo is telling or some action that the photo has captured. Or perhaps there is an atmosphere or mood that the photo is hopefully going to evoke and colour would be a potential distraction. Typically B&W can be used to emphasise or create from scratch an atmosphere of drama or mystery or threat. Colour can be comforting, and removing it is removing that potential source of comfort - which may or may not suit your purposes. B&W can also be used to evoke nostalgia or to create a vintage look, especially if it's accompanied by an appropriate tint (sepia is a common example).

As others have noted, B&W almost always benefits from generous amounts of contrast - more than you would give a colour version of the shot. If it was specifically the lighting of a scene that caught your eye, B&W can be an effective way to draw attention to that aspect of the scene.

I like B & W because I feel the viewer can get distracted by colors and not get the full impact of the image. I have set a couple of my Nikons to shoot B & W in the past; I can check the image after because it will be displayed in B & W on the rear LCD display. That being noted, a Nikon Z8, set for B & W, when you look thru the viewfinder you are already looking at a B & W image.

When I get back from a photo shoot or a Nikon holiday, I will take my favorite images from those trips and decolorize them, it is interesting to see the results and get a new perspective on the images. Sometimes Fall color images produce really cool images when they are decolorized, they can resemble IR shots to a degree.

I found for myself that shooting B & W on certain cloudy days can add "mood" to the images. Also why I prefer some clouds in the sky when shooting seascapes and landscapes. I used to not bother going out with a Nikon on overcast days; no more, at least when there is good contrast produced by the clouds, that contrast is important.

B & W can grab ya when done right. One of my favorite quotes about photography goes..."Don't shoot what you see; shoot what you feel!" YES!!! I got a good shot of the Alaska Range and Denali specifically this September past; the color image is very good but the B & W talks to me more, and has better contrast. I have the B & W hanging on a wall at home.

Some flower images look great when decolorized; take a red rose and decolorize it, sometimes the rose will appear to be a smooth grey velvet.

A good B & W has good contrast and good shadows, and its composition is more obvious, to me.

Another trick I have made use of, take a photo I have had for quite a while and flip it around, now you have a whole new image. This does not work obviously if you have text or signage in the shot.

I agree with Linda's suggestions. I do a fair amount of B/W photography but I never try to salvage a crummy color photo that way. Rather, I head out with B/W in my mind as what I will shoot that day. Certain weather conditions naturally lend themselves better to B/W shooting, like a bright overcast day or natural objects (rocks, branches) made a bit shinier by rain. But a strong composition is really important without color, as are all the usual suspects--shape, line, texture, contrast (unless you intentionally leave that out for effect), and movement through the image. I'm not technically well-versed so I'm winging it here. My processing of a B/W photo is more extreme than the same one in color, and I do a lot of playing with the color sliders--you'd be surprised at how that can change things. You can definitely train yourself to see a scene without color, and it's good practice.

The topic title is not the question to ask. If you are shooting for a black and white result, then you should be removing color from the equation mentally before you select your subject. Don't fall into the trap of comparing.

Instead, start looking for textures, tones, contrast, light and shadow, shapes. Sometimes you want to remove the distraction of color - such as in much of street photography.

If black and white "often seems depressing," you're looking at poorly conceived or executed photos: subject matter or processing.

You've already discovered how similar tones in color become blah in b&w. You've dabbled with color filters in pp, so you've seen how those affect the result. Study "tonal range" further.

If you're shooting in raw, does your camera have a setting that will display the image in black and white (in-camera only)? That can help you learn to see. Sometimes squinting reduces color saturation - that was a tip I learned with b&w film

Analyze the photos that you admire (look beyond UHH). What is it that attracted you?

I don't know of any specific books offhand, but there are tons of YouTube videos and websites with tips.

In my adventures with black and white film, I found that where color is important (e.g. flowers), B+W just doesn't work.

These days, I have a tool to help me: an app on my Android called "Hypocam". It includes B+W filters (RGBYO) and various effects.
Also, photzy•com has some free 😁 downloads (pdf), including:

"Black and White Short Guide",
"Color vs. Black And White", and
"How to Use Black and White Photography to Enhance Mood".

--Rich