Tips on writing a indie-pop song?

I have been playing guitar for 7 years and have written many heavy metal songs and heavy rock. I have recently gotten alot into pop indie, sorta death cab for cutie, hush sound, etc. I would like to start a project with this and am having some trouble figuring out how to write these sorta songs. I am used to starting with a complex guitar riff, whereas it seems these start with a catcy singing hook. Any tips/thoughts?