High five! I tried to train myself to stop erasing so much by sketching in pens, so now I have the habit of sketching in ballpoint pens when I'm just doodling... but it worked, because I erase a lot less when doing actually illustrations, too! 
I know how you feel about wanting things to look right the first time, though. It's a struggle, but as long as you're working through it and trying to remind yourself, that's what matters!
@Kann I feel like we've all had our grid paper phases. Why did we all decide to draw on grid paper, anyway?
Same with all the layer modes. But, they're just so great when you first discover them...