I have been asked about sharpening without halos. I am going to start with my Photoshop method and then discuss an alternative.
First, I do not sharpen in Lightroom. Every photo I process has a default 0.5 radius and 25% sharpening with 60 to 85% masking. This will give no halos
In Lightroom, I do use textures to get the effect of sharpening before exporting to Photoshop.
If you want to sharpen more there are ways to get rid of the halos in Photoshop. The first way is to use unsharp, then copy the sharpened layer above it. Change blend mode to darken. Using blend if, move the dark slider all the way to the right so it only fills in whites. Move the top layer 2 or 2 pixels down until the white halo is gone and merge layers.
Sometimes this does not work do to the complicated or white lines in the subject. The second method is to use selection to select either the subject or the sky. Duplicate this layer with the selection twice. Then using the expand or contract selection expand move the selection so the it goes 1 pixel into the subject. 1 pixel only. Then create a mask from the selection. On the copy expand or contract the selection to cover the halo. Move this mask to the layer the layer that has the first mask Invert as required so with the 2 masks you have combined you will have black all except for a 2 or 3 or 4 pixel wide white line (they will be separate masks) but you can see where what they would look like if on top of each other. Now you either remove mask from the top layer and move it just enough pixels to fill the halo. Remember to use darken blend mode. Now add a third mask to this layer. Fill it with black where the and paint white where the halos you want removed are. You do not have to be precise or use a small brush because the other 2 masks take care of that. Then merge and you have a sharp picture with no halos. But you make not want to do that. Sometimes the skyline looks too sharp with the whole picture sharpened. So you can you invert both masks so there is white over the sharpened layer except for a 2 or 3 pixel black over lap. Then merge it unto the original later before sharpening. The halo will be masked out and give a more natural look to the sky line. You will have to paint white on the masks over any lines in the subject.
This is the easy method I developed for prints a few years ago. I do not know of any videos or places to learn this. I did get out my AT2020s to record my flutes. While they are out, if I can figure out the OBS program, I may make a video on that and on my pre camera illustrations coloring I do for a print project and on some of Rob's edits.
There are other methods I use more often, but this is fast and easy when editing Rob's photos and what I use. One of the 2 other methods I use involve frequency separation so I can work on colors on the color layer and work on details on the detail layer. Then use color blend mode for the color layer, and Hard Mix, Linear Light, or Overlay for the detail layer. The longer method is to make luminosity masks use them. I can sharpen different zones of the photo for a more blended look. But is no where near a beginner Photoshop user process like the moving layer is.
The Alternatives:
The first is to use Darkroom which has some luminosity masks and can do some of this. I have not become proficient in this yet but did enough work to see it would help.
The second method is Topaz Studio 2.
This is far easier and very fast learning curve. In fact just do it with nothing to learn. This is not experienced me talking. It is people I have recommended it to who have never edited an image telling me they did not know how easy it was.
I got this program for noise reduction at high ISOs and it is great. I know DXO and DeNoise may be technically better. They also cost more. Studio 2 has an AI clear layer. It is basically DeNoise but only in 3 levels (although using the opacity you get whatever level you want. This also has 2 levels of sharpness (with no Halos).
Then Studio 2 has Precision Detail. Which is like textures plus as you can vary detail of different sized things in the image. So you bring out the large detail, then the medium, then the small details. You can do this on one layer or make different layers. Every layer has a mask which can be for color. Sometimes the details on red get obscured when I saturate the reds. Instead of frequency separation, I chose a color mask and do detail (sharpening) on the reds. It also has a 10 level luminosity mask so I can sharpen (or crush blacks) very precisely. Curves to crush blacks one change moves the curve at the levels. Studio 2 luminosity mask does not do that. It has infinite and you can chose how wide of a range you want it to effect. There are many other masks available and they all combine one mask very easy and fast.
Then you have Precision Contrast. This adjust the contrast in 4 levels. Added to the large, medium, low is micro contrast. Adjusting these affects the sharpness. You also have all the masking on every thing in Studio 2, so you can have 3 or 4 Precision Contrast layers for different areas (sharp contrasty clouds do not look at all natural).
After using Precision Detail and Precision Contrast, there can be halos. Since the layers are there until you export your photo, I will lower one and raise the other until I get the detail I want with no halo. It takes less time to do than to write how to. I also saved some as Studio 2 presets so I get the Precision Detail and Precision Contrast presets and am usually done. Also I may move the layers so one or the other is done first and that will get rid of the halos.
I had the trial of this and DeNoise and there as trial of DXO Photolab. I chose this one for just what is described here. I use it as a plugin for Photoshop. It does far more than this essay on sharpening mentions. It is also less expensive than the other 2 noise reduction detail maintain programs I compared it to. Almost everything it does can be done in Photoshop. I have a few pages of actions to scroll down to find the one I want. My full basic action has 23 layers and does not include the final color grading. It is just faster and easier in Studio 2. I click AI, or Precision Detail, or Precision contrast, and move some sliders. If someone is looking at Studio 2, although it is a stand alone editor, there are somethings it does not have. There is no lens correction (purple fringing, etc) no distortion or keystoning correction, and no composites. It does do spot adjustments very well. But I have a set of adjustment brushes I made for Lightroom that I use for now.