Sometimes, when many tabs open and a new tab opens, or an existing tab pulls the focus, I find it hard to return to where I was.
I was thinking about heat-coloring the tabs so I can instantly see which tabs I was working on (these will be colored red), while tabs I haven't used for a while will eventually turn blue (cold).
The coloring shouldn't be time-based; it should be usage-based, so the popularity of a tab (red color) is determined in comparison to the other tabs so even if I haven't used a specific tab in hours because I was away from the keyboard when I'd come back it will still be red because I haven't used any other tabs after I used it.