I use Day One to journal. There is a service that creates a new Day One entry from the selection, but it didn’t have a hotkey associated with it. So I’ve set one up.
First (optional) step is to use to make your CAPS LOCK key useful. Big thanks to Brett Terpstra for that, I use that for loads of other shortcuts.
Next step is to add a shortcut for the New Day One Entry With Selection using the instructions to create keyboard shortcuts in the Apple knowledge base.
I used CAPSLOCK D as the hotkey to send whatever I’ve got currently selected to Day One as a new entry, works a treat.
Note: this is ^⇧⌥⌘–D using the optional first step, so it is the same as pressing Control, Shift, Option, Command, D all at the same time.