Yeah.... My model isn't flawless https://s31.postimg.org/a7fnifsll/LRF.jpg
. There are some ways to avoid going out of the line or hiding them. Your main problem is that you just started painting and your hand is not used to holding a brush. Most of the right-hand people can't write with left hand, but they can learn, it is no more difficult than learning to write with right hand. Same with the brush, for example: you will paint the eye but you miss, because you don't have right perspective and it is hard to assume where the brush will go. I'm not too good with this too but there is some things you can do. Don't begin painting from the edge of the detail, start from the middle and move brush to the edge, some times moving to the age is unnecessary because wash will hide the gap, some times there is a good idea to lay miniature on the desk instead of holding it in the hand. Next thing is how to use the brush and what you should paint and what better to leave. Reliquary painted by my is a good example. I overdone gold frame, I wanted to paint it from each side and I went out of the line. I should just paint front side using edge of the brush, not the tip and wash would camouflaged the sides sufficiently.
To be honest I'm not the best painter. I just know few techniques and I'm trying to adapt them to my ,not to high painting skills. Painting on my level isn't that hard, there is maybe 10% skill 70% techniques and 20% right tools.