I have a meditation I like to use. I imagine myself up above a river, looking straight down. I take the time to imagine the water and the way the light plays off it, the dirt and the sticks, and the rocks that make up the banks, the trees that create the shade, the sounds and the smells that make up the scene. I try to hold all of that in my mind.
Building the scene is a fun challenge, I'm actively creating something, but holding the scene gets dull pretty quick. My mind starts to wander and, while the scene is still in my mind, I start to remember assignments I need to complete, the times I made an ass of my self, movie scenes that make me laugh.
As I try to hold this simple image thoughts constantly bubble up from my sub-conscious and my conscious mind is trying to grab them, hold them, examine and be distracted by them. And this is the meditation - my goal isn't to suppress those thoughts, it's to gently hold them as they bubble up then place them in the river to watch them drift away. It's a practice of allowing my thoughts to surface, appreciating those thoughts, then letting them go to allow others to arrive.
I've been doing it for several years and it's gotten much easier to get in that river state of mind, which I think is the space you're trying to make available.