Dave Stockton once told me that, if nothing else, aim 2.125-4" higher than your read. We subconsciously line up the ball to the center of the cup, even on breaking putts. In reality, a breaking putt enters the hole somewhere above the front center point of the 4.25" wide cup, so you can always add at least half the cup diameter to any read, and really, close to all of it, depending on break, ands still maybe "catch the lip."
And, using geometry, it can really be even an inch or so more, not to mention, most ams really under read break by about half.