i wouldn't say marketing is everything.....
just look at af1's, not a dime spent on marketing, and it's survived how long?
anyways, i think the biggest thing you can do when creating a brand image is staying true to yourself. if you're posing, people will know, and thus, it'd tarnish your brand.
put out shit you like, dont try and impress a target market you don't know about (or are part of).
if you do have a target market in mind, but aren't really sure about how to go about getting them to feel your shit, then educate yourself on them. become one of them, etc.