I would recommend consulting tips for landscape photography in general, for example, there are excellent videos on YouTube about landscape photography. Remember, the camera of a smartphone is not really that different from any other camera; Most tips on how to photograph landscapes with a digital SLR camera will apply equally if you are using a smartphone. Taking great landscapes is 99% about being in the right place at the right time, and then finding the right angle.
A specific advice for using a phone, which I can give: most smart phone cameras will have an "HDR" mode that can be enabled in their configuration. This will help with the dynamic range, that is, the bits in the photo, which otherwise would not have details because they are too dark or too bright, will have more visible details. He does it by combining several exhibitions.