Yeah.. Why not develop both at the same time?
Personally, I have a million good ideas, but it's harder to write a song than to come up with a good idea, so I just write a song and use some of my ideas where I see fit. It was a hard thing but ultimately a good thing when I had to go: It's okay to use a similiar structure as another song you like. The first rule in making good music is to know what good music is, after all.
__________________
|