The conventional wisdom is to end the dart further away from the apex the bigger the bust. My problem with that is that a larger dart needs more length to taper off nicely. I end mine much closer to the apex than any books suggest. It’s more of a vintage look and it looks better than a dimple! Another trick is to curve the very end of the dart slightly inward before you get to the end. After all, bodies are curvy rather than pointy.
If you have a shapely bustline, this can all take some practice. I always have trouble underneath because my underbust is super narrow in comparison to the rest of my, so it’s a pretty drastic tapering. I do better with little gathers than darts some of the time.