Phousi Mountain in Luang Prabang is where every tourist goes to watch the sunset. I have done that too in my first two trips to Luang Prabang and enjoyed the view on my first trip many years ago, despite the tourists. It was still an enjoyable experience and the sunset was awesome!
On my second visit I came with 10 monks whom I took on a trip for a few weeks. Visiting Phousi Mountain was the end of a great day trip and we wanted to see the sunset before we headed back. My group of orange clad friends visibly stood out of the underdressed western tourists heading up the mountain and several times some of the tourists asked me if I could move out of the way so they could shoot their photo of the monks! Just unbelievable, but what I considered to be unpolite, was turning into an unbearable situation for the monks. They could basically not walk up the 328 steps anymore because people kept blocking their way and tourists were in their face with their cameras at all times. Even when we reached the top and wanted to have a prayer in Wat Tham Phousi temple, they kept taking photos. In the end, my group stood at the north-west end of the mountain top, completely missing the sunset and they finally asked me to go down again before the sun was setting.
I really didn’t want to come back here after that disappointing experience! But during my last visit in the rainy season I took my chances in the early morning hours, despite the heat and humidity. I kept walking up the mountain and stopped at every Buddha statue and pagoda, enjoying the view over the Nam Khan river first and later over the entire town of Luang Prabang and the Mekong river. And it was my lucky day! Not a single tourist was on top of the platform. Not a single sound was to be heard. No sunset, but still a great experience. I had Wat Tham Phousi temple and That Chomsi pagoda all to myself. Though I never even attempted to back up the mountain for a sunset.