Much of it comes down to the way you sell your experiences. You can make seemingly ‘mundane’ activities seem interesting if you drill down on the specifics and tie in why they interested you.
You can also do interesting things though. If you’re at university, I’d encourage you to sign up to societies that interest you and secure committee positions.
Even if you’ve graduated, you can still find things to talk about. I find the most memorable applications are where candidates talk passionately about a hobby or interest they’re pursuing. It’s memorable because they’re clearly doing it because it interests them and not because it’s ‘impressive’. Recent examples include competitive gaming,
photography and a regular Dungeons & Dragons club!
So I’d start by thinking over what you do at the moment. You’ll have stuff you can already talk about - think about how you can portray that in your applications. And if you’re in a position where you can take on more activities, I’d start by thinking about what interests you and see how you can explore that further.