This came to my mind after I saw the following question https://stackoverflow.com/q/9033/468718 and also https://stackoverflow.com/questions/tagged/hidden-features
We, Sitecore developers know the basics.
Some even mastered the areas like EXM, WFFM, Workflow, Powershell Extensions, etc.
But what are the most hidden features or tricks of Sitecore that people barely know it exists in Sitecore?
ctrl
+shift
+alt
+r
shortcut. But to be honest, I don't think it's the best question here...