At different times over the years I would target either arrows or dots, depending how far down the lane I wanted to land the ball, found it useful to adjust entry angle by landing in a different spot without having to make a starting position or line of the ball change.
These days I'm using my start position, the arrows and a point on one of the pins as the line I want to bowl down and concentrate on a breakpoint along that line. I have an imaginary line through the 3 points and my swing line is parallel with that line. Am now using speed adjustment to change how far down the line the breakpoint occurs.
I count boards at the pins to adjust the line I'm bowling on, by using 1 board for each of following... outside left pin edge,, left side of pin base,, middle of pin base,, right side of pin base,, outside right of pin base,, gap between pins ...(as counting 6 boards)
Warning, I'm bowling worse than ever, so dont follow me