Three massively overdone concepts to avoid
1: cartoonish graphics, mascots, basically any form of vector art whatsoever. The designs might be great but honestly you'll just look like a Bape hop-on, and we know what state Bape is in right now. We already have fails like The Hundreds doing stuff like this...
2: reappropriated sports team logos, commercial logos, etc. They can be done well, I guess, like the Fictitious clothes posted below, but honestly anything subversive has the bar set high by OriginaFake, and logo editing has been run to the ground by Supreme.
3. Taking your "symbol," whatever it is or is going to be, and sticking it prominently all over everything. No matter how famous you are... look at Supreme box tees (gay), the Crooks medusa head (gayer), and whatever brand has rifles screenprinted all over it (ultrahomogay)
I'm assuming this is a streetwear brand, possibly t-shirt focused, so the following might not apply, but look at brands like Temple of Jawnz and Mister. They cut their own patterns, so they can decide to alter the fit of their clothes in addition to their designs. It'll require more capital, but it'll also make you more unique. This is my personal opinion, but to me, interesting cuts and unique little touches that really show you care are much more appealing than a Hanes tee with a nice design. I know PLAY comme des gar