Waterfall long exposure

The constraint is slowing time: to render water as a smooth veil you need a shutter of a second or two, which in daylight is far too long without help. Mount a tripod, stop down to f/11, drop to ISO 100, and add a neutral-density filter to buy the darkness — roughly a six-stop ND lands you in the one-to-two second range. A polarizer does double duty, cutting the sheen off wet rocks and leaves so their colour comes through.

Watch out for blowing the water to featureless white and for camera shake sneaking in. Expose for the highlights so the brightest froth keeps some texture, and use a two-second timer (or a remote) so pressing the shutter does not jog the frame. If the day is bright, a longer ND or a smaller aperture will get you there — but stop before diffraction robs the rocks of their bite.