If you have a camera and happen to visit a river nearby, you should try to capture the mood and mystery of the landscaping and reflections in the river.
The reflective moods of the river are best captured in the golden hours or twilight hours when some lighting is switched on around the river.
Such photography is done both from the shore as well from a spot along the river by hiring a boat with a focus on the water itself. Sling you camera around your wrist to avoid it falling into water.
Also, consider changing your viewpoint from the normal standing height to focus on water by getting down low for an 'unusual' view of the scene.
There are many moods that come out due to the reflection of the colours of the sky, lights on the shore, and reflections of the floating objects. The sparkling lights and reflections of ships, and boats are interesting subjects to capture. If you want to use a flash, use it at an angle to avoid flare.
In the pictures attached with this story, are my river reflections from my trip to Varanasi last year. These are only illustrative. You must experiment with different camera settings and view-points to get a variety of pictures of the moods of a river on your trips.