One thing you could do is practice more by doodling on paper. That creates muscle memory and once you can do them in different sizes with a consistent distance on paper, go back to the machine. The other thing - if you want points at the very end, you need to actually stop before you go back. Just keep practicing. How about matching the thread to the fabric color? Then the inconsistencies won't be so noticeable and you are more apt to give yourself permission to soldier on.