Perhaps this has been mentioned before, but a quick forum search didn’t turn up any results, so here’s a tip I just uncovered which had been hiding in plain sight…
Issue: Ever wish you could see the full editor page as you apply styles, instead of just the little preview on the Styles tab?
Solution: Just open two browser windows - one for the Design tab and another for the Styles tab. Edit the styles in one window and watch the design view update in near real time.
When a style is changed, you can now see it reflected on the design tab in context by all the elements that use it. The update isn’t instantaneous, but it’s close enough that it’s a definite improvement over the context switching when a design tweak involves multiple styles.
Here’s a recording of the design view as I tweak styles in a separate window on another monitor.