Copying a photo of a painting or sketch in 25 minutes or less.
Using a credit card to clear rocks in a stream; using the end of a pen lid to scrape out bushes and trees; using thumbnails as scrapers.
Using a candle stub for wax as a resist, perfect for wind on water, bright reflections and trees against the sky.
Building a composition of three or four items from different places.
For portability, keep everything compact as opposed to big, thick hardbound sketchbooks.
Leaving space for words, whether it's a private journal or a shared travel journal; greeting cards as a travel journal; choosing paper that will work with the pen.