With edge highlighting there are generally two tips that I start out giving.
1 - during construction of the model, make sure you keep your 'main' edges crisp. This makes it much easier to pick them out later.
2 - Use a size 2 brush. A lot of people start out by trying to use a tiny brush because they see that edge highlights are thin and delicate. The problem is this actually make is much harder work as the paint dries on the brush much quicker. Using the tip of a larger brush is, perhaps counter intuitively, much easier.
With that said, in the main they are looking good in your photos and you can always go back with your base colour and tidy them up