Mac:Want to quickly add an item to your the sidebar in your Mac's Finder windows? Press Command+T. Want to add it to the dock instead? Just press Command+Shift+T.
This shortcut has been a part of OS X since (at least) 10.6 Snow Leopard, but we just noticed it today and wished we'd known about it sooner. While it's not a rough task to drag something to the dock or sidebar, it's practically an afterthought when you use your keyboard.
You won't use it every day, but when it comes time to add an item to your preferred shortcut location it'll be a good one to know. It's a shortcut for making shortcuts! (And as always, it's a useful option in your browser when you're looking to reopen closed tabs.