Jandau said:
I only scan when I need resources for something.
However, I do visit every planet eventually to make sure I don't miss any Assignments. However, no point in scanning them, just enter orbit and see if there's a "Anomaly Detected" message from EDI. If not, move on.
Yes, I do this on my playthroughs. I never have a problem with resources.. at least never big enough for to to have to grind the planets, like a lot of people seem to be doing. I just go looking for anomalies/side quests, and after a few systems I get bored and just deplete a rich planet every now and again. That will restock all of my resources, and go hunt for anomalies again. Never had a problem with this routine.
I always get scared that if I don't scan all the planets, I will miss a side quests or something useful. So I just turn the volume low, play the Beatles on my iPod, and just spend 10 minutes blitzing the entire galaxy. Trust me, you can scan every single planet in 10 minutes, just keep an ear out for EDI, if no anomaly, move on.