Have you ever hit ⌘T and had the worthless "Fonts" dialog popup instead of what you intended to happen? To me "T" means "Tab" or "tags" depending on the application.

World's most unwanted dialog.

One example where I wanted "tags" instead of looking at the above dialog, is Evernote. So finally being fed up with the expected result of what ⌘T should do and what it was doing by default, I edited the keyboard shortcut.

This tip works across all OSX applications and it can really help out when an application doesn't allow a shortcut to be defined.

Go into "Preferences" then "Keyboard". At the top, click "Shortcuts". On the left side, click "App Shortcuts". Then click the "+" at the bottom of the right pane and add something that looks like this:

Keyboard shortcut for Evernote

One caveat here is that you must match the menu command exactly as it appears in the application. If it is a subcommand, you just enter the menu item (i.e. no prefixes are needed if it's in "Edit > Styles").