recently iv been sketching digitally, right in photoshop. i find it very efficient to have all those tools to help with the whole process, like lasso tool to select and rearrange lines as opposed to erasing and redrawing (although digital erasing is a lot easier and cleaner than erasing pencil on paper). but at the same time im worried i will get too used to it and lost my touch with pencil/paper.
just a thought. of course il keep sketching traditionally.