You want to make comics. Let's say you're a writer, which is what I know the best, being in that position myself. (What's below will often work pretty well whomever and whatever you are, though.)
You want companies to pay attention to you, so you can get work published.
Here's one way that many companies suggest doing this: come and meet them at conventions.
There are rules to doing this.
--Hygiene: bathe. Or shower. Every morning of the convention. I don't care what you normally do. Outside the con, that's your business. For the con, bathe or shower and use some deodorant.
--Don't, however, use aftershave nor perfume. I don't think comics companies will really care if you smell good, even if you are female--remember, this is a con floor. Their five senses will already be a bit overwhelmed (well, underwhelmed in the case of taste, con food being what it typically is). If you are female, the senses of sight (you're a girl!) and sound (speak up and be confident without being overbearing!) are already making you stand out. Better that you don't give someone an allergic reaction because you happen to meet someone whose nose has sensitivities.
--Clothing: business casual. Think of it as a job interview, because it pretty much is. Don't dress like a superhero, don't dress like a Time Lord from Gallifrey, don't dress like Conan or Red Sonja. Yes, you'll stand out, but this is a comics convention--there's standing out and then there's being taken seriously as someone who should be paid for what they do. Cosplay LATER, AFTER you've made all the contacts and done all the networking you wanted to do. Publishers are guaranteed to be more allergic to eccentric, unreliable nuts than they are to cologne or perfume.
--Don't even wear a Green Lantern or Batman t-shirt, even if you want to write that character--if you haven't gotten successfully published yet, you aren't going to get to write those guys yet anyway. If you're a guy, try khaki slacks and a suitjacket or something (unless you're from Canada and you're attending San Diego--you'll die from the heat. I'm from Texas, so I can almost tolerate something like that).
--Ask yourself: "If I was them, and I was in this business to make money, would I trust someone who was dressed like me and acting like me?" To be safe, you might ask, y'know, normal people this question about yourself, too.
-The Dance Game: this is my term for "when an editor is talking to someone else already, don't butt in--don't even insert yourself into that conversation. Just stand nearby and wait. Eventually, that person will stop talking to the editor, and they will leave. Then step up and introduce yourself." If the two of them make you play the dance game for longer than you can stand, go find someone to talk to at another company and come back later!
-Be brief. Don't take up more than five minutes of their time unless you have art for them to look at, and even then, when they've looked at all they feel the need to look at, and you don't have any more simple questions, stop, thank them for their time, make sure you've exchanged business cards (or if they're out, be nice about it--be sure to write down their email address or other contact information) and go. That business card exchange is your main reason for being there. Don't try to make a deal on the con floor--that's not how it works. You want to make them see that you are a professional, sane-seeming person with no body odor, and then do the rest of the follow-up later. That's it. You're just there to set up a follow-up.
--Do your homework--be sure you know what type of stuff they do. Look at their website, maybe even read a recent interview with someone who works at that company if you can find one. Theoretically you can overprepare, but you do want to avoid pitching your sci-fi/fantasy masterpiece to a publisher who hates genre stories and loves quirky non-fiction autobiographies, and the reverse is also true.
--DON'T geek out and say, at 300 miles an hour, "Oh my god I love your book Ulterior Motive Man I love it so much I've been wanting to write for it since I was 7 years old I have Ulterior Motive Man stuff all over my room at home please please let me work with you." If you do this, they may smile and nod, but they'll really be making a mental check mark on a mental notepad in a mental box next to the word CRAZY under a picture of your face.
--Even if you're able to convince them you aren't insane as far as that goes, NO HARD SELL. This means NOT using sentences like "Here's exactly why you HAVE to pick up my project..." Even worse would be "Your writers suck, I can do better." Even worse than that would be "Here's how you're ruining this beloved character I grew up with." They really, really don't want you to tell them how to run their business. Especially if you're right.
--Again, just to be clear: not too loud, not too quiet. Make yourself heard over the con floor, make sure you don't mumble or act shy. You do have to sell yourself as confident and self-assured. If you aren't, and can't fake that really convincingly for at least 5 minutes, you need to practice your social skills more before you try all this.
--As you are thinking and practicing (and you probably should practice talking about yourself, if only mentally, at the very least) what you are going to BRIEFLY say about yourself, you might also consider what there is in your background that might help suggest that you should be paid for what you want to do. Only you can answer this one for yourself. Maybe you work in a bookstore. Maybe you work with teenagers or tweenagers (kinda 9-to-12-year-olds). Maybe you have some other sort of uniquely qualifying job or uniquely qualifying life experience. (But DON'T confuse this with YOU expressing what about your personality is unique. There's a huge glut of personal uniqueness in comic book fandom--so much so that it kind of gets, amazing as this sounds, same-y after a while.)
-Again, remember: these publishers and editors are stressed and overwhelmed. Which con you're at makes a difference, too. San Diego is crazy. If you're talking to someone from a New York-based company in New York, though, at least they'll sleep in their own beds last night, and later tonight, just like always.
-Okay, so follow up with an email, unless they encouraged you to call them, which they almost certainly will not.
--After you've followed up with an email or postal letter, DON'T poke them about it in any way for at least three weeks. SERIOUSLY.
--WHATEVER YOU DO as far as what I just said goes, DO NOT CALL THEM ON THE PHONE unless they specifically tell you to. Which, again, they almost certainly will not. It's hard to stress this one enough. So let's do it again: DO NOT CALL THEM ON THE PHONE.
Well, that's about it. Behave like you think businesspeople who DON'T work in comics must act--except for doing your homework and being informed about who you're talking to. It's okay to be passionate about what you love; it's not okay to come across as one of those scary fans who flames people on internet forums, nor as a timid wallflower who needs someone to squint into your soul long enough to recognize your diamond-in-the-rough nature.
Do you know how some people on the creative side of the industry, whom you don't understand how they got in... got in? They were able to sell themselves as something worth believing in, even if, now that they're in, they are unable to convince YOU that their new direction for Ulterior Motive Man is a sane one. Don't just sneer at those people (sneer if you wish, but don't JUST sneer). You should also admit that being able to sell yourself to a publisher as a desirable, employable individual is a feat worth respecting. Work on how you can do the same, and THEN, AFTER you've made them mentally check a mental box under a picture of your face labeled INTERESTING, you may stand a chance of showing them that your talents or skills are ALSO interesting.
Before you attempt to do this con thing, take a deep breath, look in the mirror, and say, in a firm, clear voice, "Unlike everyone else the people I'll be meeting are constantly exposed to, I am a non-desperate person who not only has a life, I also have some qualities which are really going to help some really cool company make a profit."