The putting stroke is a simple action with little by the way of degrees of freedom. The stroke is merely a vehicle for you to express your skills of curve and speed perception. Keep your alignment calibrated with regular stroke focused practise and you will be free to put with confidence.
The quality of any practise and the catalyst to your development lies in the accuracy of your self-reflection on your errors.
When practising your putting be aware of all the sub-skills that are involved and which ones you want to focus on primarily.
Green reading is an absolutely essential skill but is tough to quantify and therefore, often gets overlooked. In this video are the basic concepts. Used in conjunction with a solid understanding of the 'Zero Line' and you will bring your scores down.