It was my first time to shoot waterfall since after I got serious about photography. I understand some basic now-how, as I have read several tips about it sometimes ago. Weather comes to play an important role in landscape photography, and it is no exception for waterfall photography. Sunny sky is not what you may prefer, especially when you want the milky flows of water that requires low light. This makes early morning or late evening the best times for a visit. Tripod is a must, though an extra burden. ND filter (which I cannot afford) can reduce more light for slower shutter speed.
Here are some shots I got from Khbal Spean waterfalls, also known as river of 1000 Lingas. It is 1,500m mountainous walk from the entrance to the river. The walk is scenic but tiresome especially the trip to the river.
PS: Since the air nearby waterfall normally very damp, try to protect your camera and lens from getting wet as much as possible. Moisture is the main cause of lens fungus.