- Be 45 years old and their parent (usually this is enough on its own)
- Buy a cheap Ukelele.
- Learn 4 or 5 chords.
- Play it at every opportunity.
Important disclaimer: If you want full eye-rolling and smirking, do not skip step 1, because if one of their friends or even another adult outside the family plays the Ukelele, it is quirky and cool.