When I open the firefox I see the following [0]interface rows :
1. previows/next | history | Menubar-bookmarks button | --URL BAR-- | reload | home | some addons | Decentral eyes | CookieAutoDelete | uMatrix | uBlockOrigin | Multi-Acount containers | Addons icon | Menu bar icon |.
2. Toolbar-bookmarks row | Button for unfolding the bookmarks that don't fit in such row.
3. Pinned tabs (they are only icons) | | + | unfold vertical list of the opened tabs |.
4. The page for the selected Tab.
This allows us to use two bookmarks visual groups, the ones that are unfolded through the Menubar-bookmarks, and the ones always visible when Toolbar-bookmarks are enabled (what in reality is a subfolder from menubar's bookmarks) and are shown as 2nd row in my interface. Also the easy access to Containers and the CookieAutoDelete, uMatrix, uBlockOrigin current page options are essential.
In the Toolbar-bookmarks, for being able to visually have more folders as "quick access" row line, I use acronyms as folder names (just for the first ones until fill that space). This between separators, and also mere url icons bookmarks (by removing the bookmark title name its just showed the page icon).
When one push one those folders are unfold all the related sub-folders and sub-bookmarks.
Also, equally important, the folders and bookmarks that don't fit in such row are easily accessible by pushing an icon at the right corner, what unfolds a vertical list with the rest the bookmarks. This is important because in such toolbar one usually have several hundreds of independent bookmarks and folders by topics, with infinite sub-folders and their respective bookmarks, etc.
This let us in Firefox with:
Pinned tabs, the current session opened tabs, the usability of to have the Toolbar-bookmarks with folders as topics by clicking the folder or icon, and a second different visual group of bookmarks through Menubar-bookmarks. By other side, if one want to add to those folders/topics the page that is being visited it's just needed to drag and drop the url there. Also all those bookmarks' folders have their option for to open their content in tabs.
I cannot think of browsing comfortably without such an interface and tools as a starting point.
[0] Thankfully and fortunately, with Firefox it is possible to have a browser focused in usability by enabling its options, and also to do adjustments in the interface under our needs with custom stylesheets. By default in FF the tabs are shown over the url bar, but in my case I use as base [1]customcssforfx for to put the tabs under toolbar-bookmarks, and from there I add a couple of lines with custom padding, sizes and icons. [1] https://github.com/aris-t2/customcssforfx