How to Create Realistic Photo Reflections in Adobe Photoshop

Realistic photo reflections and shadows will always be relative to the actual scene you're working on. It then becomes a case of observation of real life, and how you utilize the elements in the scene to cast shadows correctly, and how reflective surfaces reflect the other objects around them. I'm not sure that there is a generic way of rendering reflections and shadows that doesn't look "generic". Realism will always be relative.

Well here’s what I’ve done to get Realistic photo reflections effects, create a duplicate layer of the one your wanting to reflect. With the duplicate selected go to edit/transform/flip vertical then move the flipped layer down to mirror the above image. Cntrl +click on the layer to reflect (it’s now selected with marching ants)

Set foreground color to white /select the gradient tool/foreground to transparent ,now using the gradient tool draw a line from bottom to top (hold the shift key for straight line)
Play around with it to get the effect you want.
Now if you want to make a Realistic Photo Reflections of objects on water you can Go to Filter>Distort>Ripple. By moving the slider we can select the degree of wave movement on the surface of the water. Aim to create the effect of a light breeze, so keep the waves Medium sized and don’t go overboard on the amount of ripple.
There are many adjustments you can make from this point, just play with some of the settings to find what looks right for you, and also it will depend on the picture you chose.