If you're a person who uses the right side of the Dock for quick access to your most-used files, this tip's for you. Did you know that you can email files right from the Dock, without having to locate the original file in the Finder? You can. Did you know also that I'm currently so caffeinated that I can see into the future? Well, now you do. And you should know that you'll regret what you did last night.
So here's the scoop. All you've gotta do is hold down Command while you drag a document you want to email out of your Dock.
You'll see that the Dock shortcut will remain, but you'll get a new icon to drag around. Release the Command key, and if you then drop the file you're holding anywhere in the Finder, it'll make a copy. But if you drop it on the Mail icon in your Dock, your Mac will create a new message for you and attach the file, all automatic-like.
Related to this neat feature is that if you just Command-click any of your Dock icons, you'll show your item in the Finder instead of opening it. Which is another convenient way to attach files to emails, but it's also useful for, say, jumping right to your Applications folder by Command-clicking on an app. So that's like two tips in one! I get paid double, right, guys? Hello?