Images of tree-lined river banks reflecting on to the surface of calm, undisturbed water, can conjure up emotions of peace and tranquillity in the eyes and minds of the viewer of our images, particularly, if the light is 'right'.

Very early morning is ideal, because of the lack of breeze and when ideally, the early morning sun is behind you lighting up the opposite bank.

Incidentally, the closer to the water's surface you are, the better the reflections will be, but as the morning progresses and the sun begins to inch its way higher, you may have to choose a higher angle.
When photographing river banks, try to select an area where there is a slight bend, other than a perfectly straight bank (adds to the interest and don't forget the 'rule of thirds') and the branches of the trees come all the way down to the water's edge.
Imagine, if you can, if this scene was in mid-autumn. A lovely still morning, with the sun lighting up all those rich, golden colours, magic!
There is sometimes a certain amount of light loss when shooting reflections, so you will probably find you will need to open up your aperture a bit or using 'Portrait' modes on your mode dial may suffice.
Another ideal way of getting reflections on the water is, if you are facing East just before Sunrise on the banks of an inlet, or estuary when the tide has gone well out, leaving behind puddles and rock pools.
If there is a certain amount of high cloud about, you should get some great shots as the sun lights up the high cloud, well before it breaks over the horizon.
For this, you will need a smaller aperture or 'Landscape' mode) so that all will be in focus throughout the image.
Reflections can be found on almost any shiny surface. You just need to use your 'seeing' eyes and a good bit of imagination. But it's more of a case of being in the 'right' place, at the 'right' time, to get the 'right' light.

Where to find other interesting reflections:
Tall city buildings reflecting down on to a river's surface.
Coloured city neon lights reflecting on to wet roads.
Glass buildings reflecting other buildings.
Reflected shapes in shiny, or polished surfaces.
Reflections cast in the water around boat harbours and marinas from masts, coloured plastic adornments, etc. A slightly rippled surface is best for these.
You can also create some great abstracts, by photographing only the rippling reflections themselves.

Here's a great shot to keep 'em guessing:
If you have a good clear view of a city skyline, and the roof of your car has a highly polished finish, park the car in such a position that it is parallel to the city buildings. Position yourself, with your camera, at the side of the vehicle, so that when you look over the roof, you can see the buildings in front of you and they are reflected in the shiny, polished roof. Manoeuvre yourself, whilst looking through the viewfinder, to the point where the base of the buildings meets the base of their reflection, and when ready, take the photograph with a narrow aperture. The resulting image will cause the buildings to appear as though they are on the edge of a vast lake.