Over time, if you are processing your own film and not jumping all over looking for a silver bullet, your starting packs for certain magnifications will start being apparent. I look at the neg, consider the lighting of the original scene, then with a bit of history remember the last time I made a print of this type of neg/scene I was at x filter and y time with the lens stopped down two stops. I start there.
I encourage you to look at the negative on a light box and study the neg on an enlarger and with practice all this stuff becomes pretty easy. As all will agree, standardize a bit so you are repeating each time you come into the darkroom.