How do I set a custom order for folders on Windows 7 and 10?

I generally do this by simply prefixing the folders with either letters or numbers, as though they were sections of a document:

1 - Introduction
2 - Theoretical Background
3 - Methods
4 - Results
5 - Conclusions

If there are more than ten "sections", I will use a two-digit zero-padded prefix, e.g., 01, 02, 03, etc.; I've never been quite so deranged as to insist that I need this for a group of over about 15 folders. (Even if I did, I could probably manage to script the rename.)

You can make the folders a system folder with a desktop.ini file.

Create a new text file within the folder, and set the content

[.ShellClassInfo]
InfoTip=1
[ViewState]
Mode=
Vid=
FolderType=Generic

Where InfoTip=1 sets the "tag" as "1", so you can sort numerically

Then rename the file to desktop.ini.

Then set the folder as a system folder using command prompt

attrib +s "Introduction"

Then in the root folder:

View → Choose Details → add "Comments"

And sort by Comments, now the folders will be sorted according to the "InfoTip" field in the ini file as long as the folder is marked as a system folder.

Update per comments: doesn't have to be a minute apart, only creation order matters.

If you create them at least a minute apart in the order you want, you can then sort by Date Created.