The majority of my favourite superheroes have tended to be "no capes." Storm and Banshee had them, but the rest of the X-Men? Nah. IMO, they only work on certain types of characters, mostly fliers, and my characters tend not to fly. On live, I went through the mission, but only one or two characters ever had capes. It fit my Dark/Dark Scrapper. It didn't fit my Wonder Woman-style Inv/Strength.
For colours, I tend to stick close to the basic 6, plus black; very, very rarely white. Most of my characters don't have blond hair, but a few do.
Some are in spandex, some aren't. It all depends on the concept, and the concepts are all over the map. I tend to associate spandex with a Silver/Bronze Age feel. Golden Age used more "real" fabrics. Dark/Modern uses a lot more street attire. Also more modern costumes seem more intricate with details than past eras. Whenever the character seems to fit best is what I go with. Practically none of my characters use hats, because I don't like how CoH does hats.
About 90% of my characters are female, even though I'm not. I have exactly 2 huge characters (out of the dozens I've made).