Icon overlay option for overview.
When you have more than five windows open in a single workspace, they all begin to look the same in the overview, at least to me. It particularly bad on small screens, though on large screens you have more area you need to visually scan so it bad there too. I have good eyesight, to be clear.
I sometimes intentionally change the theme of individual apps just so I can more readily see them in the overview.
One could create tons of workspaces and/or close every unnecessary window but that's really more effort than it's worth, especially cause too many work-spaces just displaces the problem of finding windows.
The only way I've found to make the overview usable for me is to install the icons overlay extension. https://extensions.gnome.org/extension/60/overlay-icons/
(Note that you can change the style to a different one - the one pictured here is bad. What I found works best is to just have a very faint but large icon overlayed on window thumbnail, without any grey padding like in this screenshot. It looks very nice and doesn't obscure the window content.)
With this extension, I am able to find the windows I am looking for much faster. I hated the overview before I installed this. I suspect this is a reason why many people never get used to the overview is because they have trouble finding windows due to a lack of icons. So they just install a dock extension and give up on the default switcher. The dock also offers fixed order for pinned apps, which makes stuff memorable, so to get all the benefits of a dock, you'd ideally have to extend the concept of pinned apps to the overview, essentially making it a full-screen dock. But the icon overlay alone may be enough for most people to make the transition from docks to the overlays.
This extension is very useful and very obscure (and it might be broken with the latest release). I think many users will benefit if were shipped with gnome, or at least formally supported by Gnome.