I use it as a personal wiki at work.
It even supports LaTeX (via KaTeX)!
Here are the customizations I found useful:
* Table of Contents:
By default, there is not Table of Contents in the wiki. So a TableOfContents tiddler was added.
The tag $:/tags/SideBar adds it to the nav bar, and the field list-before controls the position.
New entries are added to the table of contents by adding the TableOfContents tag.
Note: the same code can be used in tiddlers to list tiddlers with a given tag.
* Journal:
New Journal date format was changed to YYYY/0MM/0DD (DDD, MMM DDth). This makes lexicographic ordering of Journal tiddlers to be chronological.
That is, Journal tiddlers will be sorted by date when sorted by name.
Visual theme:
The layout was changed to fluid-fixed Settings - Appearance - Theme Tweaks - Options - Sidebar Layout: Fluid story, fixed sidebar
Sidebar width: 350px
This looks particularly well when occupying one half of a wide screen.
Appearance - Code Foreground was changed to #0a5701 (green, used to be red). This affects the color of text enclosed by single tick marks.
New Journal, Attachment, Configutation, Manager buttons were added
* Plugins:
The following plug-ins were added:
KaTeX for LaTeX support;
Highlight.js for code syntax highlighting
But what makes it more powerful is scripting support. One can not only customize its look and feel using CSS but also modify its behavior with scripts. Its scripting system is very powerful, for example, one user has a build a version control system for the TW notes using the TW scripting language.
Does this help?