The first thing I do when a project is open, to get a sense of things going on around me in the model, is to toggle on Worksharing Display - Owners (see image). That gives me a quick snapshot of who else is working on things around me.
If I see a color on anything I thought I'd start working on then there is no point attempting to edit those, I'll just get a warning from Revit in response. The mere presence of colors indicate other people are around, in this context. Hovering over one element brings up a larger tool tip than the usual information we get, including which person is currently editing it.
I use the Worksets option for Worksharing Display just to see if things are obviously assigned incorrectly. Again, hovering over any element tells me what workset it is assigned to in either the normal tool tip (first thing displayed, unless Design Options are involved too) or the expanded one for Worksharing Display.
I think most people forget about or overlook the Gray inactive worksets option too. That helps me cope with my nemesis Active Workset because it reminds me which workset is active because the things around me are either bold or not (see image).
Prompted by a reply to a thread at RFO.