I think of the sound and sight of waves rolling into shore (mostly because I listened to wave sounds while first learning meditating). The timing helps with box breathing, and the “waves” gather up each thought and carry it away. And I picture my happy place, which is a decade ago sitting on the stoop with my friends before we all went our separate ways, one of the last times I recall feeling “carefree”. It’s a bittersweet memory, but extremely powerful, and helps ground the practice in reality.