This article is on the subject of Ricing (customizing) Windows.
The article is primarily focused on Windows 10 and not Windows 11. Much of what is written here is applicable to both, but you should always be careful and do proper research before you attempt any more the more dangerous customizations.

Ricing Windows is far easier than most people realize^A). I’d actually go as far as to suggest it’s easier than ricing Linux, but I won’t go too far down that rabbit-hole.
Let’s move on to the general tips.

Themes allow the user to change way more than many will initially realize. The entire look of the OS can be radically changed if the correct procedure is followed.
First, it’s recommended that you install either UltraUxTheme or SecureUxTheme. Either of them should work, but SecureUx is the one favored by most powerusers and the one I personally recommend^B).
After this is done, you should check what version of Windows you are currently on. This can be achieved by pressing the Windows Key + R to bring up the run dialogue. After this, type winver and press enter. The second line should tell you which version you’re running.
This is necessary because themes are designed for specific versions of Windows and won’t work if you don’t have the proper version. However, themes created for 1903, 1909, 2004, 20H2 will all work on 20H2 and the subsequent version. So a theme for 1903 will work on 1909-20H2, but a theme for 20H2 will not work for previous versions.
Once this is done you can go to DeviantArt, VirtualCustoms, 7themes.su and CleoDesktop to download themes. DeviantArt and VirtualCustoms requires a login to download themes. CleoDesktop only offers paid themes, so you’ll need to pay to get your hands on them.
If you don’t want to sift through DeviantArt then you can go to Windows Customization which collects most themes uploaded to DeviantArt into one place. However, you’ll still need to login to DeviantArt to download them.

Icons can be downloaded from DeviantArt and other places online. DeviantArt usually includes icon packs which are more convenient than individual icons.

Icons for shortcuts and folders are the easiest to change as they come with a convenient ‘Change Icon’ button in their properties panel. Folders have it in the customize tab.
Icons have to be in a .ico format.

To change the default Folder icon, follow this guide.
Unfortunately, it only works properly if you have thumbnails turned off. However, there is a way to have it affect that as well - I just don’t know how yet.
There are ways to change other system icons as well. However, I do not have the energy to find every guide for every kind of icon just yet.

To change the icon of some software, you need to open it in Resource Hacker. Then you simply navigate to the “Icon Group” section. Then click on “Action” (in the menu) and there should be an option to replace the icon. Then just pick an icon of your choice.
It doesn’t always work and I haven’t figured out why.

Install a program called Types. After that, it’s as simple as right-clicking on a filetype and clicking “Edit Filetype”.

Sometimes you’ll find either iPacks or 7tsp icon packs. I haven’t used either, but I do think they work.
Just be sure to make a system restore point before you change the pack.
These go through the previous steps themselves (with the exception of programs) so you don’t have to bother with changing system icons manually.

Install Winaero Tweaker and navigate to the fonts section.
Winaero Tweaker includes a bunch of other options too that are worth checking out.
Don’t forget to pick a font that covers most of the languages you speak, cause it will break something otherwise.
Some software also breaks when you do this, so be careful.

There might be an alternative to the above with, potentially, none of the downsides.
However, I have yet to actually test this to see if it is one or not. When I do, I’ll add it in here.

If you want something fancier than just a picture as your wallpaper… then you’re in luck.

• Wallpaper Engine - The standard for animated and interactive wallpapers. Costs money, but it’s one time only and very much worth it. The two LOSS alternatives can’t really compare with it, I’m afraid.
• Lively Wallpaper - A LOSS alternative to Wallpaper Engine.
• ScreenPlay - This is a LOSS clone of Wallpaper Engine
• weebp - LOSS. In my experience, it doesn’t work quite well with Cairo Desktop and it’s a bit strange.
  • AutoWall - a Front-end for weebp.
• WinDynamicDesktop - Changes the wallpaper based on the time of day. Creating wallpapers is pretty easy, although the current selection is quite poor.
  • Community Wallpapers. Some are paid.

If you don’t like the default Windows desktop shell… you can replace it.
There are currently only 3 that matter:

1. Cairo Desktop
2. Litestep
3. BlackBox

Installation is fairly simple.
Besides them, there’s also Open-Shell which allows you to customize the taskbar and start menu. Even if you switch to an alternative shell, I recommend installing this because it has a few extra neat features.

Do you, like me, enjoy Aero design? Do you also want it on Windows 10+?
Unfortunately, there isn’t much anything you can actually do.

This one is only available for version 1607 and 1703-1909. It also doesn’t work very well unless you donate. As it’s not for the latest versions… it’s also effectively abandoned.
Link to site and download here.

This doesn’t give it to you, but makes windows more transparent. If you use AquaSnap it gets a little fucky. It’s also really old… but if it works, it works.
Link to site and download here.

This is currently the only functional alternative and it happens to cost money. It also happens to be another way to have custom themes on Windows.

• PowerToys
  • Will explains later.
• Chocolatey
  • A 3rd party package manager for Windows. It’s useful for installing software and keeping it up-to-date.
• organize
  • A file management automation tool. Use it to create filters to move and delete files.
  • I’m pretty sure there’s a Chocolatey package for it.
• Min2Tray
  • A small utility that lets you minimize applications to your tray.
• Everything
  • A search utility that can search through everything instantly.
• QuickLook
  • It’s for previews in explorer and the like.
• QTTabBar
  • This adds tabs to explorer along with a few extra features.
  • This one application basically makes explorer the best file manager.

• AquaSnap
  • Modifies the window manager to allow windows to snap to the edges and each-other.
  • There’s a paid version with a few extra features.
  • If you install a theme with rounded corners, it will not work properly with AquaSnap.

• There are other guides to ricing, but they’re either severely lacking or outdated.
  • chloechantelle - This one is broken for some reason.
  • Nanami-tan guide - This one is still very much useful.