Stone wall meets a wooden wall
&quot;Look nice&quot; is a highly subjective criterion.
One approach to that sort of junction is to scribe a trim board.
One tacks a trim board in a vertical position touching the stone, and then sets a compass or pair of dividers equal to the largest gap between the stone and the board. The compass or dividers are then used to follow the irregular stone face and scribe a corresponding mark on the board. The board is then removed and the scribed line is cut, which should result in a trim board that meets the stone wall &quot;snugly&quot; (depending how well it was scribed you may need a few test fits and trimming to get it snug enough to suit.)
If the stone wall is at all prone to being wet, choose a trim board that won't rot (PVC &quot;lumber&quot; or pressure-treated.)