[*]structure or song form (verse, chorus, verse, chorus, mid-8, chorus chorus etc.) 7
[*]rhyme schemes (ABAB etc) 3
[*]alliteration (She Sells Sea Shells) 5
[*]imagery (Oh the mountains and the sky oh... ) 3
[*]rhymes (same rhymes crop up across various lyrics) 3
[*]emotions (What, another sad song?) 6
[*]themes/story line (da bitch gone done it again) 2
[*]message (what you are actually saying with the lyric) 7
[*]type of hook (poignant, flippant etc) 4
I like to make the form fit the spontaneity of the idea(s). Sometimes it fits like a glove, other times its like a brick in a bowler hat. The former can sound a little twee if not done well. The later can sound great if you dont mind the hat going out of shape.