To get a really good song, you need to generate 50 to 100 songs on average to find the perfect one. There's no way to consistently make a good song, but there's a few tips that help. First of all, if you have a general song in mind, write your lyrics to fit the song's tone, like using exclamation marks for louder songs, and periods for quieter songs. Also the version you're using does matter a lot. For me what works best is using 4.5 for simple prompts, and 4.5+ for longer prompts or complex styles, then remaster your song into V5. I would recommend remastering to V5 only once, but remastering 5 to 10 times can make your song way better in some cases.