All of the above and some others. I think a lot of my early lyrics were too literal and lacked finesse. Basically, I think the only way to get past rookie mistakes is to write a lot of songs, listen to a lot of songs and play a lot of songs.
Some of the most mind-numbing stuff I've ever read are the analytical writings about Ira Gershwin, Lorenz Hart and the Tin Pan Alley writers, but I Ithink I learned some things from it. I'm still not completely sold on the idea of syllable counts in writing lyrics, but I understand how it helps refine and improve a song.
Right now, I'm learning some of the old torch songs which were mostly composed on piano and full of challenges for a broken-down country blues guitar player. I think it's helped my composing some.