On bent I am looking just at the slope. On bermuda I look at the cup 1st to see which side the grass is falling back into the cup which indicates the way the grain is growing. I then look in different directions to look for a shiny side of the grass which indicates downgrain and then I start to look for drains or water sources to see if the grain is growing in that direction. This will also help indicate which way the slope is going towards since the designer is trying to move water off the green. I then look at the highest point around the green which also helps determine the slope. I then walk the line to feel with my feet the slope of the ground. I then look from both sides of the ball to determine the line I want to take.