meditation
Letting go of thoughts to me has always felt like a task to do while meditating, and that is not the point of the meditation or of letting go of thoughts.
Rather than it being a task and something you are actively doing, I think of it more as allowing the thoughts to pass. To not try to force them out, but to just let them be. In my mind, and it may just be me, but thinking "letting them go" always felt like its something I need to do, and that is adding another thought to your mind, the thought of needing to let the thoughts go. So instead, I see it as allowing them to go, letting them be what they are - passing thoughts.
I like the analogy of a flow of water in a river. Nothing is pulling and nothing is pushing. There is no force applied, and yet there is flow. This is how I try to see my thoughts while meditating, and in general in life. Just as they came with nothing pulling them in, that's how I should let them go, without anything pushing them out.