Before you accept any Putting Instruction from any source, including this web site, there are two questions that you should ask yourself.
Think carefully before you answer each question, as it will help you pinpoint where you should direct your attention when you practise your Putting.
If you can honestly answer that you have these abilities firmly in place, then the Building Blocks on Putting Instruction such as grip, posture, ball position and so on are nice to know, but not of particular help to you at the moment.
Your main focus to improving your Putting should be on learning how to:
Most weekend or casual golfers lack the ability to do anything consistently. The purpose of a pre-putt routine is to introduce a recognisable pattern to how you approach and execute each putt.
Your Priority on the green should always be to stroke your putt with good tempo. This is not the same as holing your putt.
If you look at the impression made by the ball on a contact decal, you will see that the grouping for the average handicap golfer is widely scattered. Contact is on the heel of the putterface, off the toe, high on the face, low on the face, and occasionally in the middle.
You can quickly assess your own ability to make Solid Contact by attaching some rubber bands (or gluing a couple of matchsticks) to your putter head either side of the sweetspot.
Then watching how the ball rolls off your putter when you putt.
Another technique is to put talcum powder on the ball as this will leave an impression on the putterface. However, for the serious student there are a number of training aids such as Dave Pelz's putting clips.
Putting instruction should primarily be built on Error Correction, not necessarily on looking good when you stand over a putt. Of course, you hope to look good as a by-product of the instruction.
Following a lesson you want to see immediate results, but this has its dangers. It is easy to correct an error by introducing another error so that the two errors cancel each other out.
However, this is NOT the path to consistent Putting.
To improve steadily you need to understand the relationship between Cause and Effect.
For example - What is my putter doing during my stroke to cause the ball to go a certain way? Errors don't arrive on the scene for no apparent reason. They can be caused through a gradual breakdown of your stroke or a lack of attention to the task at hand.
Because you can't go running off to an instructor every time the wheels of your Putting start to fall off, you must learn to self-coach.
This means that you must underpin your putting game with the necessary KNOWLEDGE that you can fall back on. This web site provides some of this information.
It is a strange phenomenon in golf that the higher the handicap golfers has, the more willing they are to instruct others on how to play. As the saying goes you should beware of 'Greeks bearing Gifts', in this case golfers dispensing tips.
A Word of Caution is that you should regard all Putting Instruction as a possible solution to a Putting fault, and not just blindly accept it as the truth.