I've included some sketchbook pages here, and also some pages from the journals that I keep whenever I go on a foreign trip. I quite often sketch anything that takes my fancy in these, including landscapes and even interesting people. They bring back memories more effectively than photographs, which helps if I later want to turn a sketch into a painting.
The journals themselves are Moleskine ruled notebooks. These are a handy size to take with you when you're travelling, and the pages take watercolour quite well. I now have quite a collection. I wish they produced one with a lined right hand page and a blank one on the left for sketching though!