I have compiled a few things which I would never include in my wardrobe if I were trying to keep up with Superman, Batman, or Spider-Man
Fishnets or anything like pantyhose
It seems some days like I can't even get out of the house without a run in my tights, let alone going out to beat bad guys around. These characters are a definite minority (pictured here is Black Canary), but the fishnets are played up for obvious sex appeal. I wouldn't need to feel sexy fighting crime, I would be more concerned with not dying. In addition to that after about 20 minutes the tights would be all torn, making you look very much not sexy. So unless there is room in the batmobile for 100 or so replacement pairs of fishnets, it doesn't seem like a good idea. Spandex isn't much better, sure its sturdier but still not very durable. Naked legs would be the worst option of all, no protection whatsoever.
I don't think in general there is much problem with exposing a little bit of your breasts, but the breasts are a pretty sensitive area (not to mention one very important to our own femininity.) I don't think I would want to be forced to expose my breasts to the elements at all times, let alone alien death rays. Especially on Jessica Alba's Invisible Woman, the cleavage makes a nice big contrasting area, perfect for someone aiming at you, which is even worse considering some major organs are right behind. I suppose if I was forced I would go with more skin here as opposed to less (as with Garner's Elektra) just so that bad guys had some other non-covered areas to aim at. Of course this is provided that I lived in a warm climate (but then you would have to worry about sunscreen all the time.)
Anything very colourful or flashy
I suppose most men think that women have to wear bright colours in order to be able to express ourselves properly. I think expressing myself properly is cool when the opportunity is appropriate, but in real life I am a science student and if showed up to school wearing high heels, lots of makeup and revaling clothing in my male dominated field, I would never be taken seriously. How so then that some woman decides to rid the world of evil that she decides to wear something which makes her visible from space? I would go with something low key
Though I like the overall protective concepts of Alicia Silverstone's Batgirl costume, there is no way I would go out looking to fight evil wearing high heels. Sometimes I can barely walk in them, let alone run. Granted the ones shown here are not that high, but seriously, women aren't generally as fast as men anyway, if we were going to beat them in a fight, a lot of that would have to involve us out thinking them. And out-thinking them doesn't mean purposefully slowing ourselves down by wearing high heels in case a photo op occurs. I might consider wearing them if I could fly, but even then I think they would be a huge detriment.
Scarlett Johansson' Black Widow has all almost right (practical uniform), but one thing which would be an almost thing to avoid would be loose hair. Sure the gentlemen out there would never pull a woman's hair, but how many supervillains are gentlemen? I would think that a lot of them wouldn't respect the rules of etiquette if it meant their plan for world domination was at stake. Also loose hair would get caught on a lot of stuff. Better to use a bun or a braid, or if you were really feeling reckless a ponytail. On the same token I would never use a cape, but that applies to male heroes as well,and suffice to say that the purely decorative scarf Ms. Marvel wears around her waist would get caught on a lot of stuff.
Earrings or any other jewelry
That's right not even studs. It is one thing to maybe get to your hair pulled, but most jewellery is in some way attached physically to our body. Also the areas we attach jewellery to generally don't grow back like hair follicles do. There are a lot of stories of people losing fingers because they were wearing rings, and even studs could get caught on something. Unless the item of jewellery is the source of your power, I say better to leave them at home. Still Anna Paquin's Rogue almost has it perfect here. A faint whisp of hair, with some almost harmless studs, plus that sturdy X-men leather uniform. But before I finish there is one more important one, maybe the most important
Any highly sexualized attire (including latex and lingerie)
This serves no purpose whatsoever unless your plan was to degrade yourself in front of your enemies. I do like the red lipstick and heavy black eyeliner though. Of all the things I wouldn't wear, I think that the lipstick and eyeliner would have to be on the opposite list - a must thing to wear. After all even with all these restrictions a superheroine uniform would still be hot, and what better way to accessorize it than with some cool makeup.