Hustla... it depends on where you want to take your brand.
In terms of designing apparel that is commercially viable in a broad sense, I would stick with some of the more trendy design elements and styles, mix in your own personal style also, and then do some pieces that are completely different then anyone else.
Consumers are really liking the detailed artwork on t-shirts, dresses, swimsuits, luggage and even some more formal wear.
For several reasons, the first is it's the trend and something different, some of the stuff is actually good detailed art, and it can be argued that it is more of an individual statement than paying $xxx for a solid shirt with a logo monogrammed, but most importantly until the advent of some recent printing technologies... the printing capabilities were not available as they are now to achieve these desired affects and looks as you will see reflected in a lot of brands such as Ed Hardy, Crooks & Castles, Malicious Manor, etc. etc.
So from an artist standpoint, this is very exciting to me, because it's like a new medium in some sense, I have taken some of my artwork that I have shown in galleries here in Dallas, had it photographed and used a subtle screen printing approach coupled with newer technologies to get across visually what I was going for.
If you're an artist with a really strong individual style ( like KidRobot, etc. ), then I would say target high end boutiques, hire good pattern designers and tech illustration designers to grade out your garments exactly how you want.
Go out to the shows, talk with the consumer, with the buyers and do some good
PR and branding, and if you know any B or A-list celebrities it really helps.
I have been developing my line of clothes for about the past 7 months and have learned a lot and done some focus groups on some of the apparel that I've created... so I currently am in the processing of fluctuating somewhere between my personal style and what is commercially relevant.
For the record I do not own any Ed Hardy, Affliction, Kid Robot, etc. stuff.
PM me if you have any questions, or possibly need any resources available to you.