When the bleach is dry, you can then draw into the bleached images. Think of this as making marks and lines on your page rather than trying to make that perfect drawing. Also think about what media you use to draw with - I'm using a biro - something that is often overlooked. You do not need expensive pens!
Although I'm doing these sketchbook project posts for the benefit of my new textile group it's also been fun to see various bloggers taking up the sketchbook challenge. Take a look at some of these: