This might end up being a long response, but, here goes....
I tried to shoot fashion in NYC, in the 90s. In the 90s. Pre-digital. So, a lot of my trials and tribulations are no longer relevant. Needless to say, it is soooo much easier to get good results now than it was then. But, now, there are many more photographers getting 'good results.' The other matter is that, back then, the work was far more individualistic because film and the related processes had much more character. You could easily identify an image and match it to a photographer. Everyone shot either a Pentax 67 or a Mamiya RZ, but everyone's images looked like they belonged to that photographer.
So, how do you get started.... My first shoot was in Ohio. I visited a small agency and showed the owner a couple of completely irrelevant images, and asked if i could test with their girls. Residing in a small market, at that time, made this process pretty easy, and i got access to a couple of really beautiful girls. They weren't NYC-model level, though. But, it gave me one day's worth of experience, and that was a start.
Later, i moved to NYC after college. I had a few pictures then, and went to a lower-tier NYC agency. Every agency has what they usually call "New Faces," which are the girls they've just signed, and who typically don't have any/many pictures in their own portfolios. If you can show a booker something promising, and you don't seem too sketchy, you can probably get to 'test' with some decent girls. It's called 'testing' or TFP (trade for prints), which means you're responsible for all costs, and provide the model with either a disc with an agreed upon number of processed/finished images, and/or a couple of prints.
Be sure to agree on the number of retouched, ready-to-print images you will provide. Also, be sure to make it clear that you will not be giving the model all the files. You don't want to provide any images that don't meet your standard.
So, anyway, i set up go-sees where a bunch of girls would come to my office, which was a design studio, and i'd Polaroid them, speak to them for a few minutes, and look through their books. I'd make notes and figure out which would work for the kinds of images i planned to make. It certainly helps to have plans in advance, so you can see the girls in a particular context, rather than just collecting Polaroids and memories, and then trying to fit them into something by recall.
At the time, i was doing all the styling (clothes), and i found a makeup artist somehow... probably through AOL(!). I did the styling myself because i had a very keen eye for fashion, having 'studied' Vogue/Bazaar for years, and i didn't trust the taste of anyone else i knew. This was both good and bad. I had that control, but it is quite a lot of work to acquire the wardrobe. Actually, what i did was just go shopping.... I'd charge clothes, masking tape the tags inside the sleeves or collars, and then return them to the stores afterward.... That worked, in every instance, but you have to be careful with everything. You especially have to be careful with shoes, as you can't return them if they've been worn. I did most of my shooting indoors/in my apartment studio, so i could tape the bottoms. I would recommend finding someone to do styling for you unless you really know fashion and want that challenge and those responsibilities.
So, we'd do the shoots. I usually took on too much, and planned to get too many different looks and tried too many different lighting setups during each day. But, that was, again, with film, when you had to wait 90 seconds for a single Pola to develop, and film was expensive, and the cameras were medium format (slow-ish).... We'd typically shoot for 8-ish hours, and i'd have two models at a time, alternating between them. You'll have to experiment to find out if that's a good way for you to work. I think i did it that way to get the maximum number of different types of images during a shoot, and to be able to work with one girl while the other was being made up and/or swapping outfits.
So, after the shoot, i'd send out the film for Clip Tests, get it back, make adjustments (a third of a stop!) and then process the rest. I'd then go over contacts, scan, retouch, and then take prints to the agent/booker. I almost never saw the models again, unless their was some sort of friendship. Usually, you would expect to be dealing with the bookers. Actually, i think i took contacts to the bookers first, and asked which they wanted printed.... I may have taken a couple of retouched prints with me, though, to show 'what could be,' because the film was just a raw starting point....
The bookers chose a few prints, and that was that. If you do well, they give you more girls. If you do really well, they give you more experienced girls, who might just not be as busy as they might want to be. The agents need to keep the girls occupied, and at least feeling like they're doing work, even if it's not for pay. And, just like you, they get better and more relaxed with each shoot.
So, that's how you start. After you've done a few shoots, you should start thinking about a website. Choose a couple of WORKING, high-end, magazine photographers, and design your site the same way as theirs. It will probably be on the 'minimalistic' side. That's what plays in the market. If you diverge from that, you'd better have a very talented designer working on it, and unless you're a graphic designer, odds are you won't really recognize a good designer....
So, once you've done some shoots, you're going to need to network and promote yourself to get some real work. I would start with small magazines and websites. To be honest, things have changed in the last ten years.... Back in 'my day,' the thing you needed was 'the tear sheet.' An actual magazine page, inserted into your physical portfolio. I have no idea what the industry is like now, now that magazines aren't as important and web media is so important. Still, though, tear sheets are probably the currency.
Work on that stuff and get some real work before you seek representation. Define your look. Don't try to shoot every kind of aesthetic. Try to develop a signature. Be kind to everyone you meet. Be respectful of the girls. Be professional.
The alternate route is to Assist. Unless you have connections, it may be quite difficult to find an assisting job without experience and/or proof that you know what you're doing. In the digital age, it may be easier. Back then, you needed to demonstrate proficiency in loading (fast!) the various medium format cameras. Probably should know how to use Profoto packs, and maybe HMI/high-end LED lighting.... Or, you might start as a digital tech, where you're in charge of copying cards to redundant hard drives, and possibly running Aperture or a RAW converter on a workstation.
Some things most people don't think about when they think about shooting fashion:
• On a real shoot, you have to lead a team. Hair stylist, MUA, clothing stylist, the model/s, assistants. And, if it's for a paying job, there is likely to be an Art Director and/or Editor, and possibly other folks involved on the client side. It's not nearly as autonomous as you might like. Take advantage of the 'testing' phase to do what you want.
• When i got into it, it was half out of a love of fashion photography and half out of love of women. But, i was out of college, in my mid-twenties, and the girls you get as "New Faces" are soooo young. 14-17. So, they were really rather 'moot,' in a way....
• Model agents/bookers are not fun to deal with. Actually, all of the people at the lower end of fashion are unpleasant to deal with. They're likely to be 'club kids,' and the like. They're flaky, outrageous, excitable.... You have to deal with 'personalities.' And the feedback you get from them may be completely ridiculous and uninformed. They may not really have a clue about photography or photographic history, or even about fashion. They may be in the business for altogether frivolous reasons. This is partially why i abandoned my hopes. I figured out that, although i love(d) fashion photography, i didn't like the fashion business or most of the people who choose to work in that business. The magazines are glitzy, but the process of getting to the pages is not. Unless you like that sort of thing.... You'll need to experience it to find out.
Also, after i stopped shooting, sites like ModelMayhem and OneModelPlace came into being. These may be worthwhile alternatives to going to small agencies to get girls for testing at the outset. These also work in small markets. If you're not in LA, NYC, Miami, i would definitely go to these sites to get my first 5-10 girls for shoots. You will, though, have to be very strong in your personal direction and styling, because these girls are not as 'industry-polished' as girls you will encounter at agencies, where bookers have prepared them for how things work. You will also find a great number of arrogant girls who really have no chance of being 'real' fashion models, but will still insist on payment and/or other unprofessional issues, like bringing 'chaperones' to shoots.... You just have to weed through.
Also....
"editorial work is what i'd want to do, honestly."
That sounds good. Editorial work is where the best work is done. BUT, be aware that editorial pays peanuts. Seriously. You can't make a living shooting editorial. Unless you become a major contract shooter. A guy like Meisel used to get a million a year to shoot editorial pages (90s money). Because he was the best shooter in the world, and Vogue benefited from having him attached. But, editorial pages don't pay much at all. A few hundred per page, probably. Models don't even make much for magazine editorial pages. Even for a cover. Editorial, though, is the gateway to advertising money, which is the real money. Editorial is the single best way to promote yourself and to develop a cohesive style/signature but it is not The Objective as far as 'career' and finances are concerned.
