I'd like to begin by saying that I've contributed to this forum on and off, a few of the vets will know me, and this guide is meant to be useable by all, Veteran RPer and newbie alike.
So let's begin, taking this in a step by step process
Come up with a concept: Fortunately league is very, very generous with it's lore, so almost any concept is viable. The first step in making your RP avatar is coming up with a basic concept. I've known people to immediately know they wanted to be a Minotaur who swings Dual Scythes, and I've known people who had to be coaxed out from an idea so simple as "I want to be something cool and strong." As with any process you need an abstract. For the sake of example we'll use the minotaur previously mentioned throughout this guide.
Be Creative: Yes, you can be a plumber that happens to shoot fireballs for some reason, but that's been reused to often you couldn't make it fresh with ought scrubbing everyone's mind of it. Don't just copy someone because they're doing well or because they're cool *cough*Sephiroth*cough cough*. You want to be known for a character you've made, not just as someone who can RP a knock-off. (Courtesy of K.D. Bonez)
What can your character do?: This is important, and usually saved til later but it's a strong second step to take. Is he a wizened grandmaster or a peasant who's picked up a pitchfork to defend his home? Can she fly or talk to plants? Wings? Fangs? Claws? Legendary blades? Go wild, have fun with it. Just be reasonable, nobody wants to RP with the character who is literally a god and has every power in the book. If your worried about overdoing it pick up an old sourcebook for dungeons and dragons, and allot your character's skills with a set amount of talent points. Using our example, he'll be a Minotaur granting him immense strength, and he'll have his ancestral weapons: a pair of scythes. Short, simple, and to the point.
Give them a personality: Most veterans can ignore this section, but for people new to RPing this is important, pick a personality and stick with it. With the exception of some very, very rare cases your character shouldn't stray from how he acts. The Executioner won't be a family man on the side. A 10 year old princess who's been raised to be proper all her life usually won't be into BDSM. For beginners pick something that reflects your personality, if your a quiet geek maybe play a mage who's never had much experience outside of the arcane library. For our example, He'll have been raised with his tribe of Nomadic Minotaur, so he'll be able to warm up to people but not immediately, and he'll always be wary of foreigners and outsiders.
Give us a backstory: Every hero has a history to some degree. Your legends, people like K.D. Bonez will have alot of story to tell, and you'll have to be prepared to tell it all over time, whether that's a drawn out monologue, or subtle reveals. Or in a shurelia http://summoners.shurelia.com/ . The more important part to this is it may be a part of how you RP. If your champion had a lost lover for example and he sees someone who reminds him of her he'll follow her to the ends of the earth. The opposite is also true, you may have ghosts of the past haunting you. Now for new characters, your writing your story as you go, your backstory can be simple "Student under an archmage" "Peasant drafted in an army" "City Slicker with nothing better to do" and much, much more. These will affect how you act, but your story is a blank book and your holding the pen. For our example we'll say he's young, raised by his tribe's chieftan, so he'll be very competitive trying to become the best he can to become a great chief someday, setting out in the world for this purpose.
The Nitpicky: Now for the last few details, Your name which hopefully you've decided on is important, don't be ridiculous please. Your alignment, should match your personality that you've decided on, if your cruel then chaotic is for you. If justice is your thing then lawful. Good and Evil speak for themselves, as does Neutral. For our example, we'll need a strong name for a Minotaur, Grennan, and a naturalistic last name so, Grennan Earthwalker, and being young and headstrong he'll be a bit Chaotic, but good natured so Chaotic good.
Last But Not Least: Don't dive straight into an expert RP, for one thing if it's 40 pages long and well established, you won't fit in so well into the story. Look for something starting, 1-10 pages preferred, as few as possible. For the newbies out there, don't get into any complicated stories, If it's a story catered for known RPers, don't necessarily avoid it, but something easier like the Hero Academy will be a bit more suited to you.
Ty for reading, post feedback and let me know how i did.
http://thepunchlineismachismo.com/archives/589 (Don't be a Mary Sue, and don't be uninformed!)