Norfolk coastline.
Drawing using just a simple pen line can be very effective. I also find it to be great drawing practice as it really makes you look at and analyse your subject matter closely and accurately (no erasing!).
Pub scene.
Pen/ink is currently my favourite medium to use when drawing. I love the boldness that a simple pen line can create and it is much more expressive than pencil. Ink is also great to use before or after a watercolour wash, I tend to mix together watercolour and ink regularly. Try it for a bold, animated effect.
These Staedtler pens are the one, they dont dry out if you leave the cap off and the ink is completely waterproof!
Peace