Here's how I did it:
Start a local game:
- tap "create new game"
- swipe to "pass & play"
- tap "pass & play" to start the game.
This game type will allow you to play by yourself, against yourself, which makes it so much easier.
You start so make a word with preferably less than 5 points (words like "on", "in", "to").
Submit the word so it's player 2's turn.
Give up.
*achievement unlocked* as long as that single word was less than 5 points.
/edit:
From the comment by HiradC, the initial star gives double the points to whatever letter you place there, so keep that in mind.