I would recommend looking at landscape photography tips in general – there are, for example, excellent videos on YouTube about landscape photography. Do not forget that a smartphone camera is really not so different from another camera; most tips on shooting landscapes with a DSLR also apply if you are using a smartphone. Taking beautiful scenery accounts for 99% being in the right place at the right time, then finding the right angle.
A specific advice to use a phone, that I can give: most smartphone cameras will have an "HDR" mode that can be activated in its settings. This will help with dynamic range, ie the bits in the photo, which would otherwise have no detail because of their too dark or too bright, will have more visible detail. To do this, he combines several exhibitions.