I think it helps to understand the evolution of comic costumes in order to make a standout character design. I find that people fall into one of two camps: People that understand a "design era" and stick to it (generally,) and people who have no idea what they're doing. I find the latter is because of a lack of comic knowledge.
When comics started becoming popular in the 30's until the mid 50's, comics were in what is know as "The Golden Age." During this infancy, most superheroes were still considered
"Strong Men in Tights." Their costumes reflected this, and they consisted of simple tights with a contrasting boot or brief. Such examples are
Bulletman, these DC characters, American Crusader, and of course,
Superman.
Into the 60's through the 80's was the "Silver Age" and what some refer to as the "Bronze Age" (or late Silver Age.) As characters evolved, costumes slowly did as well. Costumes still reflected their strongman heritage, but color combinations were becoming more dynamic, yet almost all costumes still consisted of tights. Notable examples are
Daredevil, Spider-Man, Thor, The Fantastic Four, and
The X-Men. The FF and the X-Men costumes aren't the most dynamic, but the idea was that as a team, their stranger characters (Iceman, Torch, Thing) offset the team's costumes the way a splash of color would offset an individual's costume.
Where both eras stuck with a two-color scheme that usually employed a third color as an accent, Silver Age characters moved away from the "Boots-and-Briefs" and started delving into more abstract concepts (like Spider-Man & Thor.) Coming into the modern age, costumes still kept simple color schemes but got even more abstract, like
The New X-Men.
A word about color: Because comics were marketed towards kids, and because current print methods were not always reliable, most Golden and Silver age characters shared an axiom that heroes wore primary colors and shades (lots of red and blue heroes) and villains wore secondary colors (lots of green and purple villains.) This isn't a hard rule (i.e. Green Lantern and The Thing,) but exceptions to this rule are rare.
Out of the Silver/Bronze and into the "Modern Age," as characters became darker and more psycologically complex, the simple color schemes and lines also started to phase out. Art (and by application, costumes) swayed towards a distorted and dynamic look, becoming complicated and busy compared to the earlier trends. Notable Modern Age costumes that reflect this change are
The Black Spider-Man (a less-contrast change than others,)
Cable, The Four Supermen (during Reign of the Supermen,)
WildC.A.T.s, Spawn, and
Youngblood.
Where does this leave you, the CoX player? Well, I find once most people learn about costume styles, people tend to pick an era of style they like and work within that style for most of their costumes. Some people like the Modern stuff, with trenchcoats and buckles and belt packs. Some like the classic iconic hero look with their underwear on the outside. Personally, I love the Silver Age style; I like the simple use of color combined with dynamic pattern lines. The heroes I play are inspired by The Silver Surfer, Alpha Flight, and The Hulk. That being said, I have a few costumes (mostly on CoV) that fall into the Modern era.
I find that thinking like a comic artist of a specific time and following the guidelines they set helps me find the right look for my character. I think it helps them look more professional and less like something I mashed together.