One of the keys to putting well and becoming consistent with distance control is to feel like you are rolling your putts rather than hitting them. To help achieve this, you should create a triangle with your stroke.
There is a spot on your torso which the butt of the club points (pic 1) to at address. This is the top of the triangle.
Ideally the butt of the club should point at the same point at the end of the backswing (pic 2). The shaft should also point at this same point at the end of the follow-through, completing the triangle (pic 4).
The two most common tendencies I see in poor putting is when the lead hand breaks down, or when players over accelerate through impact.
Both these types of strokes will not create the image of a triangle and will cause poor distance control. Creating a triangle with your stroke helps you roll your putts better.
Learn from mistakes
Making your practice productive is the key to improvement. There are three types of practice: block, variable and random.
The more variable you make practice, the more errors you will make in practice, which sounds bad. But this is the key to learning.
Making errors increases your skill retention and transfers your practice onto the course, leading to improved performance.