Sticks to the Back: Both possible, and done, with tiny vector-control emitters sewn into the clothing that can grasp objects you place on top of them and hold them in place against the emitters, or even at a designated range from them. And, obviously, anywhere, not just the back, including – if you care to be quite gratuitous about it – orbiting around you. (It should be noted that these are generally double-ended – the emitter grips you at one end and the object at the other, such that it doesn’t strangle you with your own shirt.)
Of course, it’s still usually considered unnecessarily showy much of the time, and they do introduce a dependency on your clothing’s power supply continuing to work, something that holsters, pouches and pockets by and large do not.
Star-Spangled Spandex: Fabric that reflects the night sky with tiny stars and nebulae (the generic kind is nebulin), especially the kind that through inbuilt tech or an AR shimmer actually has them move subtly when you’re not paying attention, was a major fashion trend back in the middle Space Age, and has remained a minor one into the modern day. Even then, it still probably wouldn’t be all that noteworthy had it not made it into the formal regalia designs for the various new offices that were being created to manage all those new spatial holdings.
It’s still not spandex. No-one wears spandex in this future.
Space Clothes: Averted; even in space, people just wear regular clothes. (Sure, they have lots of pockets, but that’s not specific to spacer culture.) The only difference is that the pure-skirt option is eliminated for both sexes (because microgravity), and the cloaks have to come with MEMS and occasional microfan thrusters to let them manage themselves as people move.
And spandex is not used for regular, day-to-day clothing anywhere. Even not in space.
Pimped Out Dress: Well, of course, for much the same reasons as The Dandy and his Distaff Counterpart, The Fashionista are so ubiquitous; namely, that arête, to be acknowleged, must be demonstrated. It’s not universally appropriate for this purpose, of course, but when it is, it is.
The ur-example of that would be the gold dress worn on several social occasions by Merété Cheraelar, EVP of Speculative Investment at Gilea & Company. And when I say gold, I don’t mean gold-colored, nor do I mean gold lamé or cloth of gold. I mean a long and slinky evening gown made from finely-woven solid gold chainmail, complete with “embroidery” made of overlain and interwoven rings of gold alloy in variety of different tints. (And with, it should be said, tiny flying microbots woven into it at various points to make it possible to move in the thing.)
As extremely pointed messages went, it was most effective.
No New Fashions In The Future: Averted over the very long term; over the shorter term, though, I beg to point out that just as with Eternal English, generational turnover is slowed way the heck down in comparison to lifespan – potentially endless – which also slows the rate of fashion change. Or, at least, the rate at which things go out of fashion (see also: Awesome Anachronistic Apparel). Fashion innovation certainly continues – but, frankly, it’s doubtful if a lot of things will ever go out of fashion at all, so long as their partisans are still living, and they don’t plan to stop any time soon.
Also played straight for a lot of ultra-formal and – especially – ceremonial dress.
Form-Fitting Wardrobe: While it’s not all tight-fitting – many clothing styles are perfectly loose and flowing – just about all clothing in the Empire and other advanced civilizations fits perfectly. That’s because it’s made to incorporate a whole passel of tiny MEMS, micromachines which ensure that it loosens and tightens and shortens and lengthens in all the right places to fit its wearer just that perfectly, no matter who they are or what they’re doing, as long as the size was approximately reasonable in the first place. It also never gets caught on things or trails in mud, remains stable in wind and weather, and brushes dirt off itself. It’s hard to avoid being stylish, really.
(This even applies to hardshell armor, but it tends to be modified to fit perfectly on manufacture, or on-the-fly with a handy nanolathe, rather than being self-adjusting.)
Man Of Wealth And Taste: Played straight with Imperial renegades, all of whom play the villainous role of a man of wealth and taste to the hilt.
Subverted, however, inasmuch as this is also true of heroes and bystanders of Imperial origin, simply because anyone brought up in the Imperial culture would sooner concede a few of their vital organs than not be thought of as a Man of Wealth and Taste (or, relevantly, a Woman, Herm, or Neuter of Wealth and Taste). There are standards, don’ch’know?