before you do anything you need to:
A. recognise your target market eg kids - babies, toddlers, teenagers, women etc etc each age group has sub departments which need to be addressed to be focused brand.
b. conduct extensive research of the market. you can start for a small project by researching large fashion houses and making pin boards of ideas themes patterns colours. check out focus groups or forums especially mothers re kids wear. if they like it they will let you know and if they hate it the will shout louder!
c. have knowledge of the up coming themes for the following seasons (most large brands are working on the three season ahead basis)
D. know your colour pallets designs for those seasons...this can be the make or break...
e. have the ability to make samples for the products for manufacturing purposes or have the ability to make large batches of products your self. ( i would recommend if this is going to be a cottage Garden project start up concentrating on bespoke lines or vintage wear. in other words making a few mid or luxury priced items ( vintage wear how ever can be two or three carefully sourced pieces which are spliced together.
f. finding the right setting to sell your product you may want to start to sell your products quickly if so online auctions maybe good as you can photo samples and post them on a mini shop and then take orders re sizes instead of making 50 of one size and only selling 2
g. have the financial backing for a large brand or the persistence for a cottage garden project.
before i forget if you ever offer discount remember discounts can do one of two things they can either off load excess products releasing trapped capital or dilute your brand beware of a discount unless your buying your resources at one then rip their arm off!