I use my sketchbooks as places to scribble when I don't feel like doing a proper drawing but want to make marks with my pencil anyway. Or I use them it for daily sketching challenges which I love or preliminary sketches for more finished drawings or paintings.
This first photo is one of several I have done from famous paintings. I find the best way to learn more about a master's work is to copy his masterpieces. I discovered allot about 'In the Conservatory' when I did this page. And also about the artist. Art Project Powered by Google is a great reference for this kind of thing.
On this second page are a couple of sketches I did in preparation for a portrait of the girl. They were really helpful and decided me on the first pose as an open smile really doesn't look good in a portrait.
These last two are from a daily sketch challenge I set myself earlier in the year. I always find my hand eye drawing skills are given a huge boost after I draw heaps and heaps and regularly.