There's a good point for dealing with "rough" intonation before anything else, when you are changing strings. Actually, you are not really even roughing in the intonation, you are moving the saddles back away from their proper intonation point (back meaning in the opposite direction of the headstock). The reason you want to do this has to do with witness points.
There is one high end luthier I know that disagrees with "setting" the witness points, so you might temper your evaluation of what I say based on that. Regardless, I think it important to set the witness points when restringing a bass. Setting the witness points means pressing down the string on the speaking part of the string at the nut and saddles. That creates a sharp break angle at both ends and eliminates a bit of a hump in the string that will naturally form there. That sharp break angle actually kinks the string at the break point. That's fine so long as the kink is in the right place, and it's only in the right place if the saddle is in the right place.
So now you have a chicken-and-egg situation. You can't intonate the string accurately if the witness points are set, but until the saddles are in the right location you don't want to put a witness point on the string. What to do? The answer is to set the saddles back of where they will need to eventually be. Set the witness point and check intonation. The saddle will likely need to be moved forward. So move it forward a bit and set the new witness point. Check again and repeat as necessary. The advantage is that the kinks you put in the string for any trial intonations will be behind the speaking length of the string where they will have no effect. Kinks in the speaking length are not good.
