Clear water surfaces are real eye-catchers when the surroundings are reflected in them - perfect symmetry. But not only lakes can be used for reflections. An old building reflected in modern window fronts, a pretty woman just touching up her red lips in a pocket mirror, metallic surfaces reflecting colored lights, puddles reflecting the sunset, bicycles reflected in the metal of a freshly washed car or a landscape reflected in sunglasses. In general, the movements of the mirror surface should be as small as possible. Water in motion, such as a river, is much less suitable for this than a motionless puddle. If the water is moving too much, a long exposure time of several seconds will help. However, you will need a tripod for this. Sometimes a rippled surface can have its charm. For pictures with reflections on a water surface, it often looks exciting not to divide the picture into thirds, but to place it exactly in the middle. If the image is then later mirrored horizontally, the viewer must first look carefully to see what is real and what is mirrored. Just hang the photo upside down. A little tip: In almost all digital cameras, you can display a spirit level in the viewfinder or on the screen. It helps to create an exact straight line and thus symmetry when taking photos.
Fun fact for smart alecks: There are everyday mirrors and optical mirrors. With the everyday mirror, a layer of aluminum or silver is applied to the back of the glass substrate. Reflecting objects must therefore pass through the glass layer twice. Thus, the reflection appears somewhat doubled. In the case of the optical mirror, the reflecting surface is located on the front of the glass carrier, which is more expensive, but gives a very clear mirror image.
Here the water surface reflects the bright blue sky with slight movements.