Now that you've made your coffee ink, it's time to paint something with it. I decided on a stylized rendering of the Seattle skyline based off of this photo:
As you can see, it's not an exact replica so we don't need to worry too much about precision.
How To Paint Seattle With Coffee
First, gather your materials. You will need: several small paintbrushes, watercolor paper, pencil/eraser, paper towel (for blotting), a jar of clean water, and your coffee ink (this can also be done with liquid India ink and/or watercolor).
Block out the buildings with a light pencil and a light hand. Don't press hard; your ink will pool in places where the paper's been dented. Afterwards, lightly erase your marks so they're only just visible (I recommend a kneaded eraser but pink's fine, just don't press too hard).
Ink should be applied from light to dark, so give your dark areas a light underpainting first. Always allow to dry before layering any ink on top.
Begin adding detail and darkening, working your way from the top down (background to foreground) to create the "dripping" affect.
Continue at this, allowing time to dry between layers. There's no shortcuts, just pay attention to the details and keep a relaxed hand. Start to add in details.
Darken certain areas you want to stand out. Actually, here's an artist's tip for you: if any part of your drawing ever doesn't make sense, make it darker. I do this aaaaaaall the time.
When you're happy with how the city's turned out, it will then be time to add in the water. To do so you are going to need to create a wet wash. First get the affected portion of your paper wet and then prop it up so it's sitting at an angle. The next thing is to take your brush and apply ink to the waterline, adding more in areas you want to drip further or be darker. You may have to work it several times to get the look you want. Just be patient, and wait for it to dry before adding more layers.
The very final step is to add a subtle sky with just the hint of clouds. Normally, you should do the background first, but it's such a light background that it doesn't make much difference to save it for last.
And there you have it! I hope you had fun.