Step 1: Type a relevant title.
Step 2: Fill body with unrelated content.
Step 3: Repeat every single year on April 1st as if you're the only person who has ever thought of this.
The key to a practical joke is wit. Calling a stranger up on the phone and then immediately hanging up is not a practical joke. In fact--contrary to popular opinion--screaming "April Fools!" after any random action does not automatically make it a practical joke, surprising I know.
One of these threads each year is expected. Heck it's even a helpful reminder as to how unfunny they are. Learn fast.