a brand gets another brand so if you could get that one brand willing to work with you, it becomes easier to acquire additional brands.
usually, they are more willing to let a store carry their accessories line first so you may wanna take that route.
they usually take into account how many stores are around your store carrying their items as well as type of customer base you have and if that fits with your store image.
it's just about being professional as well as constant calling and talking to them so they feel comfortable with you.
i should find out in much more detail in couple of weeks since that is what i will be doing.
if i get any more insight, i will let you know.
good luck