Today I did a drawing exercise for art school which involves blowing up something small and drawing it very large (A2 paper used). I found a dead leaf outside (handy that it is autumn at present) and drew this. I've put the leaf on the paper in the photo so that you can see how much bigger I had to draw it. It was a really good exercise in terms of observation and although I had a few false starts, I am fairly happy as to how it has turned out.
I still prefer painting over drawing anyday though and I get frustrated drawing and it seems to take me longer. I know that it is good for me though, especially when thinking about tone and the better I get at drawing, the better my painting will be.