How I made a character varied. I have to say, a large chunk of my hero characters originally started as pen and paper RPG characters (which is why I had so many "non-standard" heroes).
Usually I started with a character concept, picked the powers, wrote her bio (sorry, I really don't like how the guy bodies look
), picked her main outfit, then found a way to link her in to the supergroup (which quite frequently was just my main character saying "Yay! More friends!" and not being too picky about what her friends are like).
I had one or two where I started with the powers. I will admit I started two completely based on the costume bundle (barbarian and wild west). But mainly I was concept first.