I often just make things. But I have a series of 12 x 12 quilts that I hang, so there is always a use.
But for me, without a plan means I just start sewing and see what I end up with. Improv piecing. By making hexies, or dresdens, or such - it at least sounds like you have a plan for the block
The plan is to make a trial of that block.
Our quilt guild collects orphan blocks at the end of the year and has a challenge for people to take at least 10 of them and put them together into a charity quilt. As much as the blocks look totally random they always end up coming together nicely.