Use the same prompts as you would for SD 1.5. Add dreamlikeart if the artstyle is too weak.
Non-square aspect ratios work better for some prompts. If you want a portrait photo, try using a 2:3 or a 9:16 aspect ratio. If you want a landscape photo, try using a 3:2 or a 16:9 aspect ratio.
Use slightly higher resolution for better results: 640x640px, 512x768px, 768x512px, etc.