Personally I just estimate and correct. Usually I use numbers that are easy to type with the left hand so I can keep my right on the home row. If the place I'm moving to is 17 lines up, I'll likely get there with 15jjj. Even with relative line numbers turned on, that feels faster for me than stopping to look at the number. (Haven't timed it, but feeling fast keeps me in flow so that's my metric.)

Various semantic movements help a lot, too. But I never stress on hitting the target exactly, I'd rather get nearby without thinking than stop and think to get there in one command.