It is much easier to aim at a target that is closer to you than one farther away, so pick an intermediate target a foot or two away from your ball and square your putter up to that spot and use the hole for distance control purposes
Take a more lofted club because the hill will lower your shot trajectory, then move the ball back in your stance to where your practice swings made contact with the grass and open up your left foot
Keep you putting simple by developing an easy one-two count, take your backswing on the one count and the your through swing on the two count and create a constant pace to your putts