The duration of the putt is how long it takes to go a certain distance, this is a skill that very few golfers ever work on and it is integral to learning how to control the speed of your putts
The grain of a green usually grows towards large bodies of water or the setting sun, use this little trick of scraping the green to learn and understand where and what grain is
There are two types of players, those that putt on a path versus those that putt on a line, the path putter work more on feel and seeing a wide path to the hole while line putters are very specific, need a line on their putter head, and see a think line directly from their ball to the hole